David de Gea was mocked by fans after fumbling two shots in a goalkeeping drill before Manchester United's win over Tottenham at the weekend
De Gea faces a battle to reassert himself as United's No1 with Henderson having impressed after getting the nod for the last five Premier League games.
Ole Gunnar Solskjaer's side have remained unbeaten during that run, winning four in a row and conceding just two goals in the process.
De Gea played in last Thursday's Europa League win over Granada, but was back on the bench for Sunday's clash - with Henderson making several saves in the 3-1 win which saw United go seven points clear in second place.
And while Solskjaer has insisted he has two No1s, De Gea has been slammed online after footage emerged showing him failing to catch the ball during a pre-match drill at Tottenham Hotspur Stadium.
Responding to a clip of the footage on social media, one fan said: "Ole talking about De Gea playing well and being in form, having two number ones, whilst he’s doing this."
Another wrote: "No wonder de gea ain’t playing he just dropped two in the warm up."
But some fans defended De Gea, with one saying: "One of the most common techniques of catching hard shots is to drop it to the floor and pick it up. Many keepers do this Don’t talk if you don’t know."
Solskjaer insisted De Gea was merely being rested on Sunday after playing in midweek.
But United legend Roy Keane reckons his former team-mate is being diplomatic when he said he has two first-choice keepers.
"I wouldn't agree with Ole, I think he sees Dean Henderson as his number one now," the Sky Sports pundit said.
"He's given him a run of games - okay, he played De Gea in the week, which was a comfortable game.
"He's given Dean his trust in him now to play in the big games.
"He's certainly going to get until the end of the season, unless he has a complete disaster, so I think De Gea is under huge pressure now to try and get his position back in the team."
De Gea will hope for another chance to impress when United host Granada in the second leg of their quarter-final on Thursday, with Solskjaer's taking a 2-0 lead into the game at Old Trafford.
