Sunderland manager Martin O'Neill has confirmed that Carlos Cuellar will sit out the next few weeks with a hamstring injury.
The 31-year-old came off at half time in the Black Cats' 1-1 draw against Liverpool on Saturday.
O'Neill admitted his frustration at the injury, but said that he must get on with his job.
"Carlos Cuellar has had a hamstring problem so he will be very, very doubtful, not just for this game, but perhaps for the next couple of matches," said O'Neill.
"So from that viewpoint it is a bit disconcerting, but these things happen and you just have to get on with it."
Sunderland take on West Ham United on Saturday.
