Hamstrung Nani out of Aston Villa match
The Portugal international was injured during Wednesday's 3-1 win over Braga in the Champions League and United manager Sir Alex Ferguson confirmed: "Nani is out with a tight hamstring. It will be about 10 days."
Ferguson was hopeful that Jonny Evans would recover from a groin injury ahead of the game.
Evans and Nani both failed to finish Wednesday's match, being substituted in the second half, but Ferguson said that while Evans remained doubtful the injury was not serious.
"We will monitor him and hopefully he's fit, as Chris Smalling has just come back so it's asking a lot for him to play again," Ferguson said.
United go to Villa as league leaders after winning their last four matches to move a point clear of Chelsea at the top of the table.
Villa are in 17th place having won only two league games all season, one of them against Sunderland last week. United have not lost at Villa in their last 16 league visits and on current form look likely to extend that run.