John Stones has tested Gareth Southgate's patience before and is about to do so again.

The 26-year-old had hoped to banish any lingering fears he remains error-prone after thoroughly deserving his recall to the England squad following a stellar run of form with Manchester City. Injury-permitting, Stones remains the favourite to start England's opening Euro 2020 match against Croatia alongside Harry Maguire, but as was the case on Wednesday in a 2-1 win over Poland, his reliability in the biggest moments still has to be taken on trust.

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It is important to remember that Southgate will not view his latest error in isolation. England exited the 2019 Nations League semifinals after a similar mistake against the Netherlands -- adding to a growing catalogue -- and although Stones survived to earn one more call-up, he was then left out of the set-up for 16 months as he disappeared down the pecking order at City.

Pep Guardiola's side are on course to regain the Premier League title in no small part due to Stones' remarkable resurgence, and even after erring here at Wembley, the centre-back atoned in part by heading back Phil Foden's 85th-minute corner for Harry Maguire to thrash a shot into the roof of the net and spare England's blushes.

"Every player is going to make mistakes in games and sometimes they will be punished and sometimes they won't. What you are looking for is that reaction and to see how they respond. It would be easy to fold in those moments and John didn't. It was an important factor in us staying in the game, his reaction and that was important the whole team showed that sort of response.

"He's been having a good season and he's made a mistake tonight, he knows that but he bounced back during the game and he's got to keep doing that."

But Southgate already harbours concerns about the fragility of England's defence -- it is the reason why he opted for a 3-5-2 system at the 2018 World Cup and goes a long way to explaining the use of a 3-4-2-1 shape on several occasions since -- and Stones gifting Poland their equaliser will do little to assuage those fears.

Collecting the ball from goalkeeper Nick Pope, Stones turned and took a heavy touch, allowing Jakub Moder to nick the ball from him. Substitute Arkadiusz Milik slipped a pass back to Moder, who fired an equaliser past Pope.

England deserve credit for finding a way to win but just as they needed a set-piece to produce a winner--- their reliance on dead-ball situations was bordering on the excessive in Russia -- they required a soft penalty to take the lead in the first place. Raheem Sterling drove into the box and went down under minimal contact from Michal Helik, and Kane converted the subsequent spot-kick in the 19th minute for his 34th England goal.

For all their lively attacking play -- Foden, Mason Mount and Kane combined superbly on more than one occasion -- England were unable to translate their first-half superiority to the scoreline in more meaningful fashion.

And when Poland improved, emboldened by that equaliser, England laboured. Southgate and his assistant Steve Holland apply studious attention to detail to every facet of the game and so it was surprising to see them engaged in lengthy conversation -- seemingly suffering inertia -- during a sustained second-half period in which this game threatened to get away from them.

It is tempting to think it may well have done had Robert Lewandowski been playing. With the Bayern Munich striker missing due to a knee injury, Poland lacked the potency to capitalise on their increased possession.

England began to look a little jaded. Ten of this starting line-up also began Sunday's 2-0 win over Albania and it showed. The return of Marcus Rashford, Jadon Sancho and Jack Grealish will improve Southgate's options but it felt telling he did not turn to Dominic Calvert-Lewin, Jesse Lingard, Ollie Watkins or Jude Bellingham when the side need re-energising.

The England manager has some difficult choices ahead, made all the more taxing by the knowledge squad management will be more vital this summer than ever given the cumulative fatigue arising from a condensed domestic schedule due to COVID-19. England have habitually struggled with tiredness in the second half of tournament matches. Former Three Lions boss Sven-Goran Eriksson summed it up best: "First half good, second half not so good."

Southgate and Holland devised a specific plan to counter this prior to Russia -- giving the players a week off in a staggered strategy depending on when a player's club engagements ended -- but there are just three weeks between the final round of Premier League matches and England's first game. Involvement in the Champions League and Europa League finals will shorten the gap further still.

"We will still look to do that. Whether they are going to be able to go away is of course looking highly unlikely. But I think they need a rest period," said Southgate when asked about pre-Euro preparations..

"Psychologically, they would need that rest. Under normal circumstances there's clearly potentially five or six attacking players that we'd have been able to refresh the team [with] across the three games. Even though 45 minutes in the first game doesn't seem anything, as you get towards the end of the third game, all those things take their toll.

"We knew these were important qualifiers, we had to push. We've recovered and looked after the players in the best possible way but come the summer we will have more options to refresh during matches and make those changes that will allow us to rotate the squad a bit more. That is going to be key."

It is easy to only look inward when discussing England's shortcomings given the nationwide thirst for tournament success, but Germany provided important context on the same night here, losing 2-1 at home to North Macedonia. England have avoided any such embarrassment in the past week, dispatching San Marino, Albania and Poland to go two points clear at the top of World Cup qualifying Group I and put themselves on track for qualification.

But Southgate will not be judged on that. Instead, England have to build on the progress he has undoubtedly made and central to that will be finding a defence that can withstand tougher tasks than this.

The debate continues about his first-choice full-backs with Ben Chilwell selected ahead of Luke Shaw, Kyle Walker edging out Reece James, Kieran Trippier an unused substitute and Trent Alexander-Arnold left out altogether. Centre-back remains uncertain too and this close to the finals, that really isn't ideal.