De Gea struggled badly in United’s first two games of the season and suffered the ignominy of having to retrieve the ball from his own net six times in the Manchester derby.
And while yesterday’s defeat cannot be placed solely at the Spaniard’s door, his lack of ability to prevent shots and contribute in possession has caused United problems.
Chief among them is the necessitation of a deep defensive block.
De Gea’s reluctance to come off his line has seen Man United defend with the deepest defence in the division, despite Ten Hag’s preference for coaching proactive football.
His teammates actively avoid using him as a passing option, clearly aware of their goalkeeper’s weaknesses on the ball.
It makes playing out from the back that much more difficult when the team is essentially a man down in a crucial area of the pitch.
De Gea is not the only reason United have had to play deep and counter, but he is a contributing factor and Ten Hag has found himself forced away from some of his initial principles in a bid to steady the ship.
For Gary Neville, this style of play cannot last if United are to challenge for trophies.
“I think we’re seeing less success with that type of football,” he said.
“Other than Leicester, can you think of a team that has not dominated possession most of the time that have won this league in the last 15-20 years?
“Not really now, you don’t see it. You have to be a really proactive team, on the front foot, pressing, doing all the right things.
“I think [Ten Hag’s] had to step back to go forward, I think he’s had to regroup and that’s no problem.”
And the Dutchman is likely to gravitate towards his preferred system as he gets the right players in:
“We all know where Erik ten Hag wants to get this United team to.
“He wants 75 per cent possession, he wants players that can handle the ball.
“Not just actually in the middle of midfield but defenders can handle the ball, the goalkeeper needs to be brilliant on the ball.”
For De Gea, that can only mean one thing according to Neville:
“I suspect with David de Gea, his career at Manchester United is probably going to be short-lived under Erik ten Hag because he’s absolutely going to be adamant that his philosophy of playing out from the back, playing through midfield, playing those little risky passes that we see City and Ederson do all the time that we no longer see as risky because they do it so well, is something that he’s striving for and wants to get to.”
United spent much of the summer window making enquiries regarding top-class goalkeepers, with the likes of Kevin Trapp and Yann Sommer unlikely to have been targeted if the expectation was for them to warm the bench.
Given how his season has gone, it is difficult to imagine that De Gea has changed Ten Hag’s mind regarding the need to strengthen the position.