The week's two Champions League semifinal first legs were very different matches, but both offered plenty of tactical intrigue. Here's a key tactical talking point from each.

Barcelona 3-0 Liverpool: Left-backs make inroads

On one hand, this home win was all about Lionel Messi. But in a tactical sense, Liverpool managed to deny him space effectively: He found himself in the right position for a fortunate rebound in front of an open goal, and then curled in yet another majestic free kick.

On the other hand, the battle here was all about the left-backs. Jordi Alba has probably been Barcelona's second-best performer this season, while Liverpool's full-back pairing have recorded a steady stream of assists. With Trent Alexander-Arnold omitted and the more defensively solid Joe Gomez coming into the side on the right, this meant Andy Robertson would carry the attacking threat.

- Ogden: Liverpool paid price for making Messi angry
- Barca ratings: Messi a perfect 10 again
- Liverpool ratings: Robertson 9/10, Salah 6/10

Ernesto Valverde's decision to play Arturo Vidal might have been designed to stop Robertson. He was used instead of the more technical Arthur, which meant Ivan Rakitic played a left-centre midfield role, and Vidal played on the right of midfield, tasked with shutting down Robertson. He didn't always do this particularly effectively, however, and in the first half, Liverpool's bright moments came when Robertson overlapped aggressively. With Sadio Mane's speed worrying Sergi Roberto, Liverpool looked dangerous down that side.

Jurgen Klopp made no such attempts to contain Alba, aside from the concession of starting Gomez. His team selection, including a fourth midfielder because of Roberto Firmino's injury, hinted at using a defensive-minded right-sided player -- Milner, perhaps -- to track Alba. Instead, Milner played as a right-centre midfielder, and Alba was often unmarked, with Mohamed Salah staying higher up the pitch.

Alba's trademark assist is getting to the byline and cutting the ball back for his pal Messi, and on 13 minutes, they nearly combined in typical fashion. It took a superb challenge from Robertson, covering expertly and matching Messi's run, to stop them.

But Alba remained the key player. On 24 minutes, he nutmegged substitute Jordan Henderson, played the ball inside to Messi and sprinted in behind for the return pass -- the type of run he has been making for several years, most memorably for Spain's second goal in the 4-0 Euro 2012 final win over Italy, when he did something identical to this with Xavi before finishing smartly. This time, however, Joel Matip read the danger and intercepted. The ball ended up out wide with Salah, and Alba sprinted back across to dispossess him and concede a throw.

From the next move, Barcelona switched play to Philippe Coutinho, he laid the ball back to Alba, and the left-back produced an absolutely brilliant cross/through ball that met Luis Suarez's perfectly timed run for the Uruguayan to put Barcelona ahead.

Liverpool rallied at 1-0 down before Messi's double. But the crucial tactical change was Valverde turning to Nelson Semedo, a second right-back, midway through the second half and deploying him in tandem with Sergi Roberto to shut down Liverpool's left. From then, Robertson had less opportunity to push forward, and Liverpool were far less dangerous.

Tottenham 0-1 Ajax: The Dutch defenders come out on top

The most intriguing clash in the first Champions League semifinal was the battle between the defensive trios: It was Ajax past versus Ajax present.

Tottenham's trio of Toby Alderweireld, Davinson Sanchez and Jan Vertonghen received their defensive tutoring in Amsterdam, while Ajax's current triumvirate is Matthijs de Ligt, Daley Blind and Frenkie de Jong. From the outset, it was the current Ajax generation who came out on top .

Fittingly, considering the Dutch interpretation of defensive play, the superiority of the Ajax trio wasn't really about defending. It was more about their ball-playing ability. Ajax silenced the crowd by keeping possession expertly, and a crucial factor was the ability of the centre-backs, in particular Blind, to fire line-breaking passes into the feet of midfielders and attackers. One early pass into De Jong bypassed Spurs' press easily, while another similar ball toward Dusan Tadic cut through both sides' entire midfields. For the first five minutes, the atmosphere at Spurs' new ground was hugely impressive. Quickly, however, Ajax silenced the home support.

- Miller: Spurs emerge from Ajax defeat with hope

De Ligt was capable of something similar, and he emerged victorious from his physical confrontation with Fernando Llorente. It's rare to see any young centre-back so commanding in the air, let alone a centre-back who is so technically gifted and still only 19.

But the real star was De Jong, who played as Ajax's deepest midfielder but often dropped back into the defence to help Ajax play out from the back, turning their 4-3-3 into a 3-4-3. His calmness with the ball at his feet is remarkable, and he exudes a physical presence with his body positioning, belying his slenderness and relatively short stature.

Without the ball, De Jong was often performing two roles simultaneously. His primary responsibility was watching the runs of Dele Alli, who endured a quiet game. But De Jong was also always checking over his shoulder, assessing the positioning of Llorente and covering the passing lanes so Spurs couldn't hit balls into the feet of the Spaniard. De Jong was helping to nullify two of Spurs' three primary attacking threats, demonstrating tremendous tactical intelligence. It's also notable how often De Jong finds himself in position to intercept cut-backs from the byline.

Spurs' defenders were solid enough, though Vertonghen was forced off toward the end of the first half after he suffered a nasty blow to his head. That forced Spurs to reorganise and use a diamond midfield, which prompted an improvement, as the energy of substitute Moussa Sissoko helped them compete in the centre of the pitch and carry the ball forward toward goal more directly.

But Spurs struggled to create clear-cut chances, and even when they mounted spells of pressure in the second half, they found that Ajax's defenders were capable of doing the ugly stuff too. Alderweireld and Vertonghen had a great partnership together in Amsterdam and have reprised it in the colours of both Belgium and Spurs. Nevertheless, with De Ligt and Blind plus De Jong dropping back between them, this is a superior central defensive base.

Sri Lanka Cricket believes that coach Chandika Hathurusingha and Ashantha de Mel will have no issues working together in the Sri Lankan dressing room, after the pair is said to have "thrashed things out" prior to the latter's appointment as team manager and selector-on-tour for the World Cup starting at the end of this month. Since de Mel took the reins as chief selector ahead of Sri Lanka's tour to New Zealand, the pair had clashed over several selection choices - most notably the exclusion of Dinesh Chandimal and Lasith Malinga's captaincy.

"Before the appointment we got the both of them together to talk things through," SLC secretary Mohan de Silva told ESPNcricinfo. "They eventually thrashed things out and now we're very confident that they'll work quite well together."

De Mel's appointment, which was rubber-stamped by SLC at an executive committee meeting on April 30, had been mooted for some time, but speculation had been rife over whether he and Hathurusingha would be able to get along over the course of the six-week tournament.

It was a spat with the new selection committee that culminated in Hathurusingha being removed from the role of selector-on-tour in February. And since then Hathurusingha's job security has only become more tenuous.

In March, he was given "a break" during Sri Lanka's T20I series against South Africa after rumours surfaced of him having fallen out with certain players and staff. The situation was so dire that SLC CEO Ashley de Silva flew over personally to hold crisis talks, following which Hathurusingha returned to the island for further mediation. During this period, there were also reports of SLC seeking legal advice over possible options with regard to prematurely terminating Hathurusingha's contract which will only run out in 2020.

However, following clear-the-air talks with the board, Hathurusingha is understood to have agreed to rein in his methods as a "total dictator", much of which de Silva believes had manifested during the course of the nine-month SLC power vacuum, when the governing body was run by a sports ministry-appointed competent authority.

"We were in two minds whether to discontinue him or not," de Silva said. "We needed to know if he was amenable to our way of thinking and whether he would change his attitude. Because to be quite honest, he had become a total dictator after we left, and that's also one of the reasons that the selectors were gunning for him.

"But he has now promised to toe the line with the administrators and the selectors, because to be honest his thinking in terms of the national team has been good, although the results haven't followed unfortunately."

Sri Lanka will begin their World Cup campaign against New Zealand in Cardiff on June 1.

Three security officers from the Ministers' Security Division (MSD) will accompany the Sri Lankan team for the World Cup in England and Wales.

This follows a move from Sri Lanka Cricket to put in place additional security measures following Easter Sunday attacks in Colombo on April 22.

"SLC made a special request for additional security, and as such we managed to procure some of the best officers from the MSD," said Sri Lanka's Sports Minister Harin Fernando.

"The ICC has already assured security and these officers will be working closely with them. We had no issues granting SLC's request as this is no time to take unnecessary risks."

This move is a deviation from the norm; at previous ICC tournaments, where Sri Lanka Cricket has relied solely on tournament security provided by the host country.

The attacks that left nearly 300 people dead has impacted Sri Lanka's preparation for the tournament. A motivational camp in Maduru Oya and a training camp in Dambulla have been cancelled in the past week.

The team began training a few days ago and will leave for England on May 7, giving themselves a little over three weeks to prepare before their World Cup opener in Cardiff against New Zealand on June 1.

Toss Mumbai Indians chose to bat v Sunrisers Hyderabad

Mumbai Indians captain Rohit Sharma went against the trend and decided to bat against Sunrisers Hyderabad in a bid to seal a playoff berth. Rohit wanted to take a chance on a fresh Wankhede pitch, despite having the dew factor in mind. The hosts were unchanged compared to two made by Sunrisers.

The visitors picked Martin Guptill to replace David Warner while Basil Thampi came in for Sandeep Sharma. Mumbai need to win one of their remaining two games to make the playoffs whereas a win for Sunrisers on Thursday will pretty much seal their playoff berth because of their superior net run rate.

Mumbai Indians: 1 Quinton de Kock (wk), 2 Rohit Sharma (capt), 3 Evin Lewis, 4 Suryakumar Yadav, 5 Kieron Pollard, 6 Hardik Pandya, 7 Krunal Pandya, 8 Barinder Sran, 9 Rahul Chahar, 10 Lasith Malinga, 11 Jaspreet Bumrah

Sunrisers Hyderabad: 1 Martin Guptill, 2 Wriddhiman Saha (wk), 3 Manish Pandey, 4 Mohammad Nabi, 5 K Williamson (capt), 6 Rashid Khan, 7 Vijay Shankar, 8 Abhishek Sharma, 9 Bhuvneshwar Kumar, 10 Khaleel Ahmed, 11 Basil Thampi

Big Picture

Right, here we go then: England are about to hit the home straight, going into a home World Cup. And yet, they might not feel quite so at home in Malahide, where Ireland will be looking to add to their troubles after a rocky week for the ECB. England's management have spent most of the build-up dealing with the fallout from the Alex Hales affair (an ongoing series), so the chance to play an actual cricket match will be a pleasant change in that respect.

Ireland rarely need much motivation when it comes to upsetting the English, but a few weeks out from a tournament in which Eoin Morgan - who switched allegiances exactly a decade ago - is hoping to lead his much-touted England side to a first global 50-over trophy… Well, that would go down like a pint of the black stuff at Gibney's. Not least because this is the first World Cup at which Ireland will not be participating since 2003.

England may be the No. 1-ranked ODI nation, but it won't be the No. 1-ranked team who walk out in north Dublin on Friday. Hales' fall from grace aside, there are numerous absentees through (mostly) minor injuries and prescribed rest for England's IPL contingent. However, the confirmation of a debut for Jofra Archer, the most-talked-about potential World Cup star yet to have played a single ODI, does add a layer of anticipation from an England perspective.

That aside, this is as much of a chance for James Vince to audition for Hales' spot in the World Cup squad (if England don't just give it to Archer); possible ODI debuts for Dawid Malan and Ben Foakes, who is in line to take the gloves after the shoulder injury that cruelly ruled out Sam Billings; and the jostling among the pace bowlers, with Chris Jordan, like his "little bro" Archer, trying to barge into World Cup contention.

Any sniff that England are taking this game lightly would only encourage Ireland further, but there should be no room for complacency in the wake of recent disruption. Hales was part of the camp that got together at the weekend but was subsequently removed to protect the England team "environment" - with Morgan now having given a frank assessment of how the squad felt. Morgan can at least point to England's record against Ireland on his watch, with victories in Dublin in 2011 and 2013 (plus a washout in 2015), and last year's 2-0 win on home soil.

For Ireland, the opportunity to claim a major scalp burns brightly - their last win over a Full Member (other than the recently promoted Afghanistan) came against Zimbabwe at the 2015 World Cup. They will also host West Indies and Bangladesh in a tri-series later this month, while the new FTP and forthcoming ODI league marks the next stage in their bid for more fixtures. But beating England, and emulating Scotland's heroic effort in Edinburgh last year, would start their season on a sweet note.

Form guide

Ireland WLWLL (last five completed matches, most recent first)
England LWLWL

In the spotlight

For a long time considered one of Ireland's most-promising talents, Andy Balbirnie has taken the long route to becoming a linchpin of the batting. He was released by Middlesex in 2016 and battled injury for a period but has blossomed in the last 18 months, scoring three ODI hundreds in the pivotal No. 3 spot. With Ireland's class of 2011 slowly heading towards retirement, Balbirnie's development has helped offset the loss of Ed Joyce, in particular, and at the age of 28 he should be coming into the prime of his career. Made a career-best 145 not out to guide Ireland to victory over Afghanistan in March and comes into this game on the back of another hundred for his province, Leinster.

There can be no other candidate. Fortunately, Jofra Archer looks a player born to be in the spotlight, having blazed a trail around the world in T20 leagues from the Big Bash to the IPL since making his debut for Sussex in 2016. His story is now well known: left out of the West Indies squad for the U-19 World Cup, he decided to make use of a British passport and set out to complete the seven-year qualification process to represent England. A change of rules reduced that period to three years and the clamour to get Archer involved in time for the World Cup has only grown since then. A 90mph bowler who can blast sixes and pull down the toughest catches, now is his chance to make an irresistible case.

Team news

Stuart Thompson has been ruled out with a shoulder injury, with former Warwickshire allrounder Mark Adair called up in his place. The spine of the team is full of experience, but there could be a debut for 19-year-old left-armer Josh Little.

Ireland: (possible) 1 William Porterfield (capt), 2 Paul Stirling, 3 Andy Balbirnie, 4 Kevin O'Brien, 5 James McCollum/Lorcan Tucker, 6 Gary Wilson (wk), 7 Mark Adair, 8 George Dockrell, 9 Tim Murtagh, 10 Boyd Rankin, 11 Josh Little/Barry McCarthy

With Roy injured, Jonny Bairstow rested and Hales jettisoned, the stage is set for Vince and Malan to form England's newest opening partnership. Joe Denly is set for his first ODI appearance in almost 10 years, with Jos Buttler, Ben Stokes and Moeen Ali among those given time off after the IPL. Ben Duckett and Jordan are the other options in England's 13-man squad.

England: (possible) 1 James Vince, 2 Dawid Malan, 3 Joe Root, 4 Eoin Morgan (capt), 5 Joe Denly, 6 Ben Foakes (wk), 7 David Willey, 8 Jofra Archer, 9 Adil Rashid, 10 Liam Plunkett, 11 Tom Curran

Pitch and conditions

A classic green seamer that could have been designed for Tim Murtagh's nibbly medium-pace. Having been undercover for the last two days, it is unlikely to be a deck for breaking batting records. It was raining in Dublin on Thursday, but the forecast for the match is for a largely clear - if bitingly cold - day.

Stats and trivia

• Ireland's only ODI victory over England remains the 2011 World Cup win at Bengaluru, when Kevin O'Brien went ballistic.

• Gary Wilson is set to win his 100th ODI cap for Ireland.

• Morgan is about to go past James Anderson (194) on England's list of most-capped players in ODIs, with only Paul Collingwood (197) above him.

Quotes

"He is exciting. The attributes and skills he has are good enough to play international cricket, it's how he deals with the pressures that come with it and how he performs." Eoin Morgan on the prospect of Archer's debut

"England have knocked the benchmark up again in ODI cricket over the last couple of years. They've given ODI cricket an extra nudge. They're knocking scores up by about 40 runs regardless of the surfaces they're playing on."
Will Porterfield on the challenge posed by England's hard-hitting batsmen

Joe Clarke and Tom Kohler-Cadmore, the pair of highly rated England Lions batsmen, have been informed they will not be considered for selection until further notice.

Clarke and Kohler-Cadmore were named during the trial of Worcestershire allrounder Alex Hepburn as members of a WhatsApp group that exchanged disrespectful messages about women in what the judge described as a "pathetic sexist game to collect as many sexual encounters as possible". Hepburn was jailed for five years earlier this week having been found guilty of rape.

While neither Clarke or Kohler-Cadmore were charged - the judge clarified in his summing up that Clarke "did nothing wrong" on the night of the attack - it is understood the ECB was concerned by the content and tone of the messages. The ECB's Cricket Discipline Commission is currently deciding whether to bring a case against either man and has informed them they will not be eligible for selection - either for the full England team or the Lions - until those deliberations, or the subsequent disciplinary proceedings, have reached a conclusion.

The ECB withdrew Clarke and Kohler-Cadmore from the Lions squad to tour India earlier this year for the same reasons.

Clarke's current suspension is particularly pertinent. He has started the 2019 season in fine form - he made 112 and 97 not out on Championship debut for Nottinghamshire and is currently averaging 53.16 in this year's Royal London one-day competition - and might well have been in line for selection for the ODI in Dublin on Thursday.

England are without several first choice top-order batsmen, either through injury or being rested after the IPL - while Alex Hales was dropped after failing a drugs test - so have recalled the likes of Ben Duckett (averaging 28.80 in the Royal London Cup) and Dawid Malan (averaging 34.60). Had Clarke been available for selection, there is a strong likelihood he would have won a call-up.

Hepburn, Clarke and Kohler-Cadmore were all team-mates at Worcestershire at the time of the rape in April 2017. Clarke joined Nottinghamshire at the end of the 2018 season, while Kohler-Cadmore left for Yorkshire midway through 2017. Steve Rhodes, who was Worcestershire's director of cricket at the time of the crime, was sacked for not reporting Hepburn's arrest to club officials in a timely manner and stood down from his position as England coach for the Under-19 World Cup.

DOHA, Qatar -- Track and field's governing body will immediately apply its testosterone regulations to the 1,500 meters, president Sebastian Coe said Thursday, ignoring advice from the Court of Arbitration for Sport.

The CAS said Wednesday that there was not enough evidence to show Caster Semenya and other female athletes with naturally high testosterone levels had a significant advantage in that event.

The CAS upheld the IAAF's rules limiting testosterone for athletes competing in some events, including Semenya's favored 800 meters, in its landmark ruling.

But in a caveat to the decision, the Switzerland-based court specifically said there was "a paucity of evidence" to apply the rules to the 1,500-meter and one-mile races. The CAS asked the IAAF to delay the rules in those events until it provides more evidence.

Asked a day later at a news conference in Doha, Qatar, if the IAAF would heed that advice from sport's highest court, Coe simply said: "No."

Despite saying the IAAF would ignore the CAS' advice on the 1,500 rules, Coe said he was "really grateful" to the court for its overall decision.

Having answered two questions from reporters on the CAS decision, Coe refused to speak any more on the issue.

Coe's response to the 1,500-meter question fuels Semenya's argument that the IAAF is deliberately sidelining the South African star because of her success. The two-time Olympic and three-time world champion in the 800 recently put more focus on the 1,500 as an alternative. She won a bronze medal in the 1,500 at the 2017 world championships.

Semenya, 28, gave her strongest criticism yet of the IAAF when she said in a statement in the wake of the CAS decision: "I know that the IAAF's regulations have always targeted me specifically. For a decade the IAAF has tried to slow me down, but this has actually made me stronger."

Semenya now has the option of submitting to the IAAF rules and medically reducing her testosterone to be able to compete in the 800 or 1,500 at major meets. Or she could run longer distances and not have to medicate. She hasn't indicated what she will do.

Semenya and another athlete who has publicly announced she has a testosterone condition, Francine Niyonsaba of Burundi, will both run in the 800 at the Diamond League meet in Doha on Friday.

It will be the last top-class women's 800 before the testosterone regulations go into effect next week.

The Oakland Raiders are expected to re-sign veteran running back Doug Martin, a source confirmed to ESPN's Paul Gutierrez on Wednesday.

Martin's anticipated return comes after Raiders running back Isaiah Crowell tore his Achilles tendon during a workout with the team Tuesday and was ruled out for the season, sources told ESPN's Adam Schefter on Wednesday.

The team's move to bring back Martin was first reported by NFL Network.

Martin showed he had something left in the tank last season, rushing for a team-high 723 yards after he replaced an injured Marshawn Lynch as the Raiders' bell-cow back in Week 8. It was the third-highest single-season total of Martin's career.

Martin, who turned 30 in January, rushed for four touchdowns, and he tied Lynch for the team lead in averaging 4.2 yards per carry -- a big jump after he averaged 2.9 yards per attempt in 2017 for the Tampa Bay Buccaneers.

Martin also caught 18 passes for 116 yards, though he had some ball control issues, with three fumbles.

A two-time Pro Bowl selection with the Bucs, who selected him in the first round (31st overall) of the 2012 draft, Martin was released in 2017 following two tumultuous seasons. He entered a drug rehabilitation program and was suspended for the final game of the 2016 season and the first three games of 2017. He then was benched in favor of Peyton Barber for the final three games of the 2017 season and was a healthy scratch in Week 15 for violating a team rule.

In seven NFL seasons, Martin has rushed for 5,356 yards and 30 touchdowns. He has caught 148 passes for 1,207 yards and another two TDs.

The Raiders used the No. 24 pick in the draft on Alabama running back Josh Jacobs and also have Jalen Richard, DeAndre Washington, James Butler and Chris Warren on the roster.

Tiger Woods is set to celebrate his Masters victory by visiting the White House and President Donald Trump on Monday, according to multiple reports.

The reports say Trump will host a ceremony honoring Woods, who won his 15th major championship last month and fifth green jacket.

The day after the victory, Trump tweeted that he had spoken with Woods and announced he would be honoring him with the Presidential Medal of Freedom, the nation's highest honor for a civilian. That presentation is expected to take place later in the year.

The president is an avid golfer who played a round with Woods at Trump's golf club in Jupiter, Florida, in February.

KANSAS CITY, Mo. -- Linebacker Derrick Johnson will be the next player to sign a one-day contract and retire as a member of the Kansas City Chiefs.

Johnson said by text message he would sign the contract next week.

Running back Jamaal Charles signed a one-day contract with the team on Wednesday so he could retire as a Chief.

Johnson, 36, was the Chiefs' first-round draft pick in 2005 from Texas. He played 13 seasons with the team and was one of the NFL's top linebackers for much of that time.

Johnson was selected to play in the Pro Bowl four times and was a first-team All-Pro in 2011. Johnson has 27.5 sacks and 14 interceptions for the Chiefs.

The Chiefs released Johnson last March. He signed with the Oakland Raiders but lasted just six games before the Raiders released him.