The Spaniard was at fault for two of Chelsea's goals as United fell to a 3-1 defeat by the Blues, but United boss Ole Gunnar Solskjaer has vowed to support the shot-stopper.
He said: "(David) knows he should save them 100 times out of 100 but that's football for you.
"It is done. Move on. I know he is a mentally strong person and goalkeeper."
de Gea has made a number of mistakes over the past year, leading to question marks over his future at Old Trafford, but Solskjaer will remain loyal to his goalkeeper.
Asked if he would stick by de Gea, the 47-year-old coach said: "Of course. We have been unbeaten for 19 games and both Sergio [Romero] and David have played really well in that run.
"We have kept clean sheets, and on Thursday night, he made some great saves against Crystal Palace. I see where you're coming from and everyone is going to make headlines on David, but he knows he should have saved that one.
"I can't speak for his confidence but he is mentally very strong. Everyone has to perform and has a chance to stake a claim every time they play.
"It is hard for a keeper to make amends, apart from David making two or three fantastic saves."
BBC pundit Alan Shearer suggested that De Gea should be replaced by Dean Henderson - who is currently on loan at Sheffield United.
Speaking on the BBC's coverage of the match, he said: "I think you only bring Dean Henderson back to Manchester United as the number one, or you keep him where he is to keep gaining experience. I think that time has come."