Sir Alex Ferguson will take a late check on his squad before finalising his line-up for Saturday's FA Cup fourth round tie at Liverpool.
Wayne Rooney and Phil Jones (both ankle) and Rio Ferdinand (back) are amongst those who are thought to be causing concern.
Nani (foot) is expected to miss out, although there has been no official update on the winger's fitness since he limped out of last Sunday's win at Arsenal.
Midfielder Jay Spearing could be recalled to Liverpool's squad after missing three matches with a hamstring injury.
Manager Kenny Dalglish has to assess the fitness of his players after their Carling Cup exploits against Manchester City in midweek, with forward Craig Bellamy seemingly the most unlikely to play three games in a week.