Steve Bruce has admitted that John Mensah is unlikely to play any part in the busy Christmas schedule after suffering an ankle injury.
The Sunderland centre-back picked up the problem during Saturday's 1-0 victory over Bolton and had to be taken off midway through the first half.
With Titus Bramble and Michael Turner also out Bruce was forced into a defensive reshuffle after bringing on Egyptian winger Ahmed Elmohamady.
Mensah has been plagued by injuries throughout his Black Cats career and Bruce expects him to be sidelined again for the next few games.
The manager told Sunderland's official website: "John Mensah has got a bad ankle.
"It's unlikely we'll see him in action over Christmas."
Sunderland face Blackpool, Blackburn and Aston Villa over the next fortnight but first travel to Old Trafford on Boxing Day to meet Manchester United.
Bruce will be without Lee Cattermole as well as Mensah for the clash with the Red Devils after the midfielder collected his fifth yellow card of the season.
Bruce believes the decision to book Cattermole against Bolton was unfair, although he was later fortunate not to get sent off following another challenge.
"It was a harsh booking but I do think he got away with another one - thankfully it was our day," said Bruce.
"He is going to be a miss for Manchester United, of course he is, but at least it's over in a couple of days with having the games so close together and we'll have him fit and ready to go for Blackpool on the 28th."