Manchester United defender Phil Jones is to have an X-ray after suffering a facial injury in the 5-0 win at Fulham.
Jones appeared to take a knock to the face in a challenge with Fulham forward Clint Dempsey early on in the first half at Craven Cottage.
United manager Sir Alex Ferguson said: "Phil Jones got an elbow to the jaw and we'll send him for an X-ray. It doesn't look good."
Ashley Young will also be out for two to three weeks with a knee problem.
The winger was forced off in the second half after a challenge from Dickson Etuhu and is likely to miss the whole festive period.
"I thought the challenge on Ashley Young was aggressive. We're all right in the striker department, it's in other areas we are picking up injuries."
Losing England international Jones for what could be six weeks would be a major blow as the 19-year-old versatile defender has been in fine form for United since signing from Blackburn Rovers in the summer for £16m.
Ferguson already has a long injury list that includes Nemanja Vidic, Anderson, Darren Fletcher, Tom Cleverley, Fabio and Michael Owen.
Defender Rio Ferdinand also missed Wednesday's win because of a foot injury and will not be fit for the Boxing Day clash with Wigan.
United face Wigan and Blackburn at home, Newcastle away and then an FA Cup third round tie against Manchester City in 13 day's over the busy festive period.
MAN UTD'S CURRENT INJURY LIST
Nemanja Vidic (knee)
Darren Fletcher (illness)
Rio Ferdinand (foot)
Michael Owen (thigh)
Anderson (knee)
Tom Cleverley (ankle)
Fabio (hamstring)
Phil Jones (jaw)
Ashley Young (knee)