It has become the issue that Ole Gunnar Solskjaer really didn’t want to confront but now cannot ignore.
Manchester United wanted to concentrate on adding extra firepower to their attack this summer and perhaps signing a commanding centre-half.
But after David de Gea’s latest error-strewn performance, Solskjaer will have to make one of the toughest decisions of his time in charge at Old Trafford.
The Spanish goalkeeper has rescued United on countless occasions in the past few seasons of under-achievement, but the mistakes and misjudgments that have crept into his game are starting to make him a liability.
The latest example came at Wembley on Sunday when De Gea, whose positioning was questionable for Olivier Giroud’s opener for Chelsea, was most definitely at fault for Mason Mount’s second as the ball slipped through his grasp.
And this wasn’t an isolated incident. There have been question marks over De Gea for a couple of years now with a number of unnecessary goals conceded.
Naturally, Solskjaer has defended De Gea in public, describing him as the ‘best goalkeeper in the world’ a few weeks back and insisting this week that ‘David is mentally strong enough to know his job.’
But privately the United boss will know that the point is coming when he needs to remove De Gea from the firing line and think about his place as United’s No 1 long-term.
The good news is that United won’t have to spend any money to bring in the keeper maybe needed to challenge De Gea or even usurp him.
Dean Henderson has enjoyed two excellent seasons out on loan at Sheffield United, helping them to promotion into the Premier League last season and then playing a major role in an unexpected top-half finish this.
As Sportsmail reported on Tuesday, United will hold talks with the 23-year-old when he returns from Bramall Lane.
But Henderson has no intention of serving as De Gea’s understudy and wants assurances that he will have the gloves ahead of the Spaniard in the important games.
If that cannot be guaranteed, then Henderson, also tipped to be a future England No 1, would prefer to take another loan or move elsewhere. Chelsea have expressed an interest.
So Solskjaer won’t be able to shirk making a difficult decision in the coming weeks and he will certainly complete plenty of analysis to decide whether Henderson really represents an upgrade on someone who has 41 appearances for Spain.
Looking at the stats, it cannot be denied that Henderson has enjoyed a better season than De Gea. With both clubs in the Premier League, it’s a fairer comparison this season to last.
In 35 top-flight matches, Henderson has conceded 30 goals at an average of one every 105 minutes and has 13 clean sheets to his credit.
De Gea has played 36 games for Man United – all of them in the league – and conceded 35 goals at an average of one every 93 minutes and has kept 12 clean sheets.
It says much about the improvement in United’s back line since they signed Harry Maguire that De Gea conceded 54 goals in 38 games last season and only managed seven clean sheets.
There isn’t much between the two keepers when it comes to saves and the percentage of shots on target saved. Henderson has made 96 saves to De Gea’s 91, the Englishman keeping out 75.8 per cent of shots to the Spaniard’s 72.2.
So there really isn’t a great deal between the two keepers in terms of performance – until you reach the statistic about errors leading to goals.
Henderson has been culpable for just the one goal in the Premier League this season as opposed to three by De Gea. And that three came off the back of four last season.
It represents a startling rise – or should that be fall – from the early part of his United career when De Gea only made a total of six errors that results in goals in his first seven seasons at Old Trafford.
Now he has committed seven errors in the past two seasons, suggesting that something has gone wrong with his game.
Against Watford back in December, De Gea allowed Ismaila Sarr’s effort from distance squirm from his grasp and into the net in comical fashion when it should have been an easy catch.
In the game with Everton at Goodison Park in March he dawdled on the ball, allowing Dominic Calvert-Lewin to close him down and deflect the clearance back into the net.
And against Tottenham in United’s first match post-restart in June he failed to keep out Steven Bergwijn’s shot that really should have been a comfortable save.
That was the moment that sparked Roy Keane’s rant on Sky Sports, the former United captain declaring he was ‘sick to death’ of De Gea and that he would have been ‘swinging punches’ at him in the dressing room.
And of course that were before his latest calamity against Chelsea in the FA Cup semi-final.
It’s also without taking into consideration De Gea’s suddenly suspect positioning, his weakness at the near post and occasional discomfort in passing the ball out from the back.
Yet he remains a superb shot-stopper most of the time and a definite points-saver and match-winner for United.
Four times he has been the Player of the Year at United during his time there and at times during the barren years under David Moyes, Louis van Gaal and Jose Mourinho, he spared the club humiliation.
But at the moment, it has to be said that his confidence looks shot. He can no longer be relied upon in every situation, he is no longer making saves he should be making.
And Solskjaer will see that on the weight of evidence and the stats that Henderson is performing better.
It will be an enormous call to drop De Gea – who signed a new four-year, £375,000-a-week contract at United only last September – but Solskjaer has shown a ruthless streak since he took over.
But there comes a time when every player must come under scrutiny, especially if their errors prove a hindrance to the team’s ambition.