Ole Gunnar Solskjaer has revealed that Bruno Fernandes could miss Manchester United's meeting with Liverpool on Sunday.
The United manager told his pre-match press conference that this week's Champions League win over Atalanta came at a physical cost.
"A great comeback, which will bring some knocks and bruises, which normally you will expect," said Solskjaer.
"It's still Friday, the game's on Sunday, we'll give everyone time.
"We might have the whole squad back fit, we might be two or three players down, today we didn't have everyone. Let's see Sunday."
Solskjaer revealed that Fernandes is one of those battling to be fit on Sunday.
The Portuguese playmaker played the full 90-minutes of Wednesday's 3-2 win at Old Trafford, but his manager may have to factor without him when Jurgen Klopp's side come to town.
"I'll give everyone time," said Solskjaer, "I hope I can pick from a fully fit squad, I might be without two or three. Bruno might be a doubt but he's doing everything he can to be ready."
The United boss also gave an impassioned defence of midfielder Fred.
The Brazilian international was replaced by Nemanja Matic on Wednesday night, and has again come in for criticism for his performance.
But Solskjaer doesn't need convincing of Fred's abilities.
"Fred is a very good player," he said, "He's a regular for Brazil, which in itself is a mark of quality, he's got an exceptional personality and attitude to football, such a big smile, and at present, I can't say if he's gonna be fit or not but he'll give everything he can to be there for us.
"He's sharp, he's nimble, he gets to players, he's never afraid.
"The development he's made in the last two and a half years I've been here has been great to watch.
"It showed when he got injured last season, six to eight-week injury and he was back the day before the Europa League final, joined the training session, strapped him up for the game.
"If I'd known before maybe I'd have played him but he would put his hand up and sacrifice himself for the team, that's for sure."