David Moyes has all-but ruled Robin van Persie out of United's Capital One Cup tie with Liverpool on Wednesday.
The Reds striker suffered a groin injury at the Aon Training Complex last week and subsequently missed Sunday's Manchester derby defeat at the Etihad Stadium.
While it is only a mild strain, the boss does not believe Van Persie is ready to return - although he is optimistic about fielding the Dutchman against West Brom on Saturday.
"I don't think Robin van Persie will play on Wednesday, but he has an outside chance for Saturday," Moyes told reporters at a press conference on Tuesday.
Expanding on his plans for Liverpool, the boss also discussed the prospect of rotating his squad for the visit of Liverpool: "I think my idea was always to focus on every competition. It's always been the way here to win. In many ways the Capital One Cup has been a route to give as many young players an opportunity as we can.
"I think the draw sometimes in the Capital One Cup is the reason sometimes you can do that. Obviously this is a really big tie that has come out of the hat first."