Ruben Amorim has revealed Mason Mount is set for another long spell on the sidelines following his latest injury picked up in the 2-1 win against Manchester City.
The midfielder was forced off after 14 minutes at the Etihad Stadium in what was just his fourth Premier League start of the season.
Mount saw a specialist on Wednesday to determine the extent of the damage.
Asked how long Mount will be out for, Amorim said: "Several weeks. I don't know the exact date but it's going to be for a long [time] and that's it. That's part of football, you continue."
Mount has struggled with injuries throughout his time at Old Trafford. In 18 months at the club, the 25-year-old has only completed 90 minutes once and never in the Premier League.
"What I can do is help Mase to teach him how to play our game," Amorim said.
"When he's recovering, try to use that time for different things. The worst part is that we don't have time to train like we should do after a lot of injuries.
"It's really hard to recreate the game before they come to the game. With Mason, we are going to help him. It's really hard for the player to be out for so long. He's trying really hard. If they try really hard we will help him to the end."
Amorim is set to decide on Saturday whether Marcus Rashford will be involved against Bournemouth at Old Trafford on Sunday.
Rashford has been left out of the squad for games against City and Spurs and on Tuesday revealed he wants to leave the club.
Amorim confirmed that the decision to omit him from the squad against Tottenham was not connected to the interview in which the 27-year-old said he wants a "new challenge" and again suggested he is being left out because of his performances in training.
"No, it's the same thing guys, it's the same thing," he said.
