The centre-back has yet to make an appearance for the Black Cats in the current campaign, having picked up the problem during pre-season.
"It would be great if he was fit and available, but just as we speak he has had a setback again and he will be out for a few more weeks than we thought," said O'Neill.
"He has been out for a fairly lengthy time already and I am quite sure his ability and experience could help us, absolutely. He has been out for so long."
Sunderland lost 1-0 to Aston Villa at the Stadium of Light on Saturday.