Wayne Rooney admits Manchester United have fallen below the club’s high standards this season.
United beat Crystal Palace on Saturday to win a record-equalling 12th FA Cup, but the triumph was soon overshadowed by speculation Van Gaal was on the verge of leaving the club which will be confirmed by the club on Monday.
Van Gaal will be replaced at the United helm this week by former Chelsea manager Jose Mourinho.
Turgid performances and a failure to qualify for the Champions League left Van Gaal vulnerable at Old Trafford, and Rooney accepts expectations have not been met.
“He has been under pressure. I think we all have,” the Red Devils captain said.
“That’s part of playing for Manchester United and managing Manchester United – it is a massive club.
“You have to set standards and we fell below them this season.
“But we have to make sure as players we get back to those standards and make sure we are back challenging for the main trophies.”
Former United defender Phil Neville expects Jose Mourinho to bring success – if not over a long period.
“I can’t see him staying too long at Man United, maybe two or three years – that seems to be his shelf-life at a football club,” Neville told BBC Five Live’s Sportsweek programme.
“When Jose finishes at a club it tends to be a pattern where he falls out with a few players, he gets disgruntled and the team dips.
“It happened at Chelsea, it certainly happened at Real Madrid where there were rumours he fell out with a few players.
“It’s a pattern with Jose. He comes into a club, he gets success but he doesn’t stay for too long.”