Liverpool are facing a problem. In six months they could lose three of their best players -- Mohamed Salah, Trent Alexander-Arnold and Virgil van Dijk -- for nothing when their contracts expire.

The chances are that at least one of the high-profile trio will extend their deal -- Salah, 32, and Van Dijk, 33, are more likely, while Alexander-Arnold, 26, seems set to move to Real Madrid -- but the club should certainly think about possible replacements for all three in case the worst happens.

Here's a list of new players who could be the best fit for each position next summer.

Centre-back (to replace Virgil van Dijk)

On the surface, finding a world-class central defender might not appear the trickiest task given the quality of candidates. Yet Van Dijk is arguably the best centre-back in the world, and no data or traditional scouting methods are going to miraculously toss up a ball-playing defender who is such a natural leader, fast, unbeatable in the air and whose game-reading skills are so impressive that he hardly needs to make a tackle.

BEST FIT: Jonathan Tah, 28, Bayer Leverkusen

Tah was outstanding for Leverkusen last season, and has been equally dominant this campaign. There are several factors that make his profile a pretty close match to that of Van Dijk: he's physically imposing, a leader who plays with an air of calm, is an extraordinary distributer of the ball (4.6 progressive passes per 90 minutes) and his elevated reading of the game ensures that he only goes to the ground as a last resort (0.5 tackles per 90 minutes.) In addition, he hardly ever misses a game through injury, and his contract expires in the summer, meaning he will be available as a free agent.

Barcelona and Bayern Munich are reported to be interested in making a summer move, and there still are a few doubts for Liverpool. Tah hardly covered himself in glory during Leverkusen's 4-0 defeat at Anfield in November, mostly features in a back three, and is coming towards the end of his career. But he's the best fit to replace Van Dijk.

OTHER OPTIONS

Marc Guéhi, 25, Crystal Palace: The England international has been linked with a 70m return to his former club Chelsea, but could also see Liverpool come in for him. This season he lined up as the left centre-back in a duo (prior to Crystal Palace boss Oliver Glasner switching to a back three), despite being right footed, and has even deputised as a defensive midfielder.

Further to his credit, he is club captain when Joel Ward is out and is often lauded for his leadership. He has pace in abundance and defends the box well, but his aerial game leaves something to be desired (62% success rate is on the low side) and his progressive passing may be exposed in a possession-heavy side.

Castello Lukeba, 22, RB Leipzig: Lukeba has been on the radar since he broke through at Lyon at the age of 19, though he has had an underwhelming debut season at Leipzig. Exceptionally quick and agile, Lukeba is also a fine passer of the ball who is typically tasked with bringing it out of defence.

Being left-footed, he'd naturally slot well into the spot vacated by Van Dijk and much like the Liverpool captain, he prefers to use his strength, speed and agility to dispossess opponents instead of diving into tackles. He is also years away from his prime.

Ousmane Diomande, 21, Sporting CP: One of the strongest defenders around, Diomande is brilliant in the air and plays with admirable supplies of confidence for one so young. He's so good on the ball, but is likely to be viewed as too adventurous and still needs to improve his decision-making.

He could have been an intriguing signing to play alongside Van Dijk rather than replace him.

Micky van de Ven, 23, Tottenham: One of the quickest centre-backs around, Van de Ven anticipates the game well, defends on the front foot and is left-footed. Few can match the Dutchman for his attacking contributions -- progressive passing and advancing with the ball -- but he is under contract for another 4 years and there's no way Spurs would entertain offers from a rival.

Alessandro Bastoni, 25, Inter Milan: Another dominant left-footed central defender. Bastoni is solid at the back -- though being supported by two additional centre-backs makes life easier -- and he's one of the most productive in Europe from an attacking perspective (distribution, carries). However, his transfer would cost around 100m.

Right-back (replacing Trent Alexander-Arnold)

Just as with centre-backs, scouring the European football scene for a readymade right-back to replace Alexander-Arnold is tricky. Accomplished right-backs at the right age and available for a cheap fee are in short supply, so it's just as well that the ideal candidate is already wearing Liverpool colours.

BEST FIT: Conor Bradley, 21, Liverpool

Along with Chelsea's Malo Gusto, Manchester City's Rico Lewis and Tottenham's Archie Gray, Bradley is among the top U21 right-backs in the Premier League. Though his technical profile differs significantly from Alexander-Arnold, he's shown enough to suggest that he'll flourish as a regular.

While you may lose something in Alexander-Arnold's composure, playmaking quality and set-piece proficiency, with Bradley you gain the more classic full-back abilities such as ferocious, high-speed ball-carrying, relentless take-ons, and a contagious attacking mindset. Bradley may not have played as much as he'd hoped to under new boss Arne Slot this season, but given the youngster's impact from the bench (and last season's displays), he will surely be a regular soon.

Of course, Liverpool would then need to find a backup for Bradley as well, so one solution could be to look at one player who could cover two positions.

OTHER OPTIONS

Jules Koundé, 26, Barcelona: A player who could actually help replace both centre-back (Van Dijk) and right-back (Alexander-Arnold). Excellent in both positions, signing Koundé could turn out to be a masterstroke. Landing an indisputable starter for Barcelona and France might divert from Liverpool's usual modus operandi but given the chaotic state of the Catalan club's finances, an opportunity may arise. Though Koundé mostly occupies the right-back slot these days for club and country, he has vast experience playing centrally as it was his original position at Sevilla.

Entering negotiations over an indispensable player with two years to run on his contract won't be easy. The huge upside, however, makes it worth a try. Koundé would have little trouble adapting to the Premier League and would offer Slot confidence in playing out from the back, the pace to push the defensive line up the pitch, and the smartness to intercept the ball early.

Amar Dedic, 22, RB Salzburg: If you promote Bradley, you'll need a backup and the Bosnia & Herzegovina international could be a good fit. He may have gone off the boil since his fine debut season two years ago, yet with his all-action, aggressive interpretation of the right-back role, Dedic would be worth a look. His 2.7 successful take-ons and 3.5 possession regains in the opposing half per 90 minutes paints a picture of a defender who is extremely attack-minded and capable of shifting into pressing mode in a split second.

Comfortable on his left foot too, Dedic could even be an option as a long-term replacement for Andy Robertson in the left-back role where Liverpool's depth is questionable.

Forward (replacing Mohamed Salah)

If the other two were tough, it gets even more complicated here. How do you replace a floating forward/winger hybrid who guarantees 20-plus goals per season, a ton of assists, and is playing the best football of his life at 32?

The Liverpool hierarchy are not short of creative minds, yet even with their track record they're up against a challenge here. Most of the like-for-like replacements -- such as Arsenal's Bukayo Saka, Chelsea's Cole Palmer, or Real Madrid's Vinicius Jr. are untouchable, while an up-and-coming youngster won't get anywhere near Salah's numbers yet.

The club's most likely way out comes through team effort, but if Salah leaves, then at least one new attacker is needed in addition to the tactical measures that Slot can employ in order to grind more goals out of the group. Recruiting an out-and-out centre-forward is arguably the most logical step.

BEST FIT: Victor Osimhen, 26, Galatasaray (on loan from Napoli)

Half a year on from his bizarre loan move to Galatasaray, the Nigeria international is still one of the most prolific strikers in world football. While his stint in Turkey has been successful (10 goals in 13 league appearances), some suitors -- Chelsea and Man United reportedly being among them -- may have moved on to other targets due to the lack of clarity in negotiations with Napoli. But he does reportedly have a 75m release clause that comes into effect at the end of the season.

Though Osimhen is unlikely to settle for a wage package significantly short of what Salah is earning now, the 26-year-old is still one of the top penalty area strikers, with pace to burn and experience that could easily see him score 20+ goals a season in the Premier League.

OTHER OPTIONS

Benjamin Sesko, 21, RB Leipzig: Young and full of potential, Sesko is more like a typical Liverpool signing. It's likely that the 6-foot-5 Slovenia international was already under consideration last summer before the club decided to give Darwin Núñez more time to settle.

As much as he's highly rated across Europe for his tremendous shooting ability, long-distance running and opportunistic positioning, Sesko presents an interesting dilemma for Liverpool. Can they justify paying the required 70m to sign a centre-forward who averages only 14 goals per season in the Bundesliga? Should they wait until he averages 20? And if they do, will another club move in first?

Alexander Isak, 25, Newcastle United: The Sweden international is as close as you come to a guarantee when looking for a striker who can score 20+ goals a season in the Premier League. With three years left on his contract, the chances of prising him away from St. James' Park are microscopic, regardless of how keen Newcastle are on trimming their squad and any move would be over 100m.

Viktor Gyökeres, 26, Sporting CP: Isak's strike partner for Sweden may have scored a goal for every league game he's played for Sporting (50 in 50), but having spent 80m to bring in Nunez from Benfica in the same league this is a non-starter. As unfair as it seems -- different teams, different skillset, different nationalities -- Liverpool (regardless of whether the analytics say they should) will surely leave this 80m bet to Manchester United given he only has a year or two at the top level under his belt. And they will take the punch if they live to regret it.

Jonathan David, 25, Lille: If Liverpool didn't already have Jota and Nunez on their books, David might have been a sound option. Out of contract in the summer, he is a first-class finisher who boasts excellent movement and has plenty going for him. What he's not, though, is a legitimate successor to Salah. And at the current stage of his development, adding the Canada international would unnecessarily clog up the attacking pecking order.