Since arriving at Manchester United in 2011, David de Gea has helped the club win more than his fair share of matches.
But over the past 18 months, more and more mistakes have begun to emerge in his game, and after another error-strewn display cost United a place in the FA Cup final against Chelsea on Sunday, questions will continue to be asked of the man Ole Gunnar Solskjaer continues to dub "the best goalkeeper in the world".
For years, Spain international De Gea has been the safety net behind a somewhat-dubious United back line. His cat-like reactions and acrobatic shot-stopping have saved the Red Devils more times than many can remember since joining from Atletico Madrid.
But, since Solskjaer took the managerial reins, his form has fallen off a cliff.
Solskjaer has been busy building an attacking unit to rival the best in the Premier League, but De Gea has become an unexpected weak link who is beginning to cost the club who made him the world's best-paid goalkeeper in September.
Even in the short period since English football restarted following the coronavirus-enforced break, De Gea has struggled.
He was at fault for Steven Bergwijn’s goal at the Tottenham Hotspur Stadium in United's first game back while he was also beaten at his near post by Junior Stanislas in their 5-2 home win over Bournemouth.
Solskjaer has routinely stuck by his number one, saying after the 1-1 draw at Spurs : "He might have saved it, he might not. But he makes great saves for us. He wins games for us. I still think he is best goalkeeper in the world."
The Norwegian coach can be forgiven for publicly backing his player, but, in reality, he has been far from the best in the world for a long time.
The clock is now ticking on his time as United's undisputed first-choice goalkeeper as Dean Henderson continues to impress out on loan at Sheffield United , and, if things do not improve, Solskjaer may have a decision to make as early as this summer.
De Gea's performance at Wembley was the nadir of his slide into mediocrity. Handed a rare start in the cup after Solskjaer decided against using Sergio Romero, he was at least partly at fault for each of Chelsea's goals in their 3-1 win.
With a forgettable first half winding down, De Gea was unable to keep out Olivier Giroud's deft near-post finish after the France striker got the wrong side of Victor Lindelof to meet Reece James' cross.
Though a clever finish from the France striker, the ball was directed more or less straight at the goalkeeper, only for it to burst through his hand and dribble over the line.
Solskjaer sent his side out early for the second half, but anything that was said at half-time was undone within two minutes by another De Gea mistake.
After Brandon Williams gave the ball away inside his own half, Mason Mount struck a tame low shot from 25 yards that De Gea somehow failed to gather down to his left.
By the time the goalkeeper was again beaten at his near post after Harry Maguire diverted a cross towards his own goal, the knives were already being sharpened by fans and critics alike on social media.
De Gea will be glad ex-United captain Roy Keane was not on television duty after his claims during the Tottenham match that he would be "fighting" the shot-stopper in the dressing room if he continued to make such basic blunders.
While De Gea will take the brunt of the criticism after his shocking display, Solskjaer himself is not totally blameless when it comes to the result.
The Norwegian was in a quandary over how much rotation was necessary to ensure progression to the final while keeping his squad fresh enough for the final two games of their league campaign as they bid to secure a top-four finish.
His tinkering, which saw United deploy a back-three and left Anthony Martial, Paul Pogba and Mason Greenwood on the bench, backfired, with United putting in a disjointed performance against opponents who had had 48 hours extra to prepare.
Solskjaer did revert to the 4-2-3-1 formation that had seen his side put together a 19-match unbeaten run shortly before the break after Eric Bailly was forced off with a head injury and was replaced by Martial, but it was not enough to alter the flow of the game.
Chelsea were well-drilled and clearly a little fresher, with Frank Lampard's side deserving of a result that could not be marred by Bruno Fernandes' late consolation from the penalty spot.
For Solskjaer it is back to the drawing board with West Ham and Leicester City to come in their final domestic fixtures of the campaign.
Whether De Gea can cut out the errors will go a long way to deciding which way those defining games will go.