The Netherlands international was injured in the victory over Bournemouth and manager Erik ten Hag, who had feared his compatriot would be sidelined for even longer, said he will not feature again until August.
“It is his knee,” Ten Hag said. “In the long term it is looking really good and he will be back for the start of pre-season. The rest of the season he is out.”
Van de Beek has only started six league games in a troubled spell at Old Trafford and Ten Hag expressed sympathy for the former Ajax player, who was hurt in a challenge with Marcos Senesi.
He added: “Everyone’s thoughts are with him. It is terrible when you are in a season and you get a bad tackle and a bad injury. It is always really disappointing and thoughts and feelings are with the player. You express that.
“We are now happy his knee in the long term is good. In the same moments, there are mixed feelings and disappointment he is out of this season. The players are feeling we are building something good and we want to be part of it and everyone wants to be part of it.”
United will be also be without Diogo Dalot for Saturday’s derby against Manchester City while United are waiting to see if Anthony Martial will be fit to lead the line. Wout Weghorst’s loan move from Burnley has not been completed in time for the Dutch striker to play.
“I think we are close but he won’t be available,” Ten Hag said.