Sunderland were dealt a major setback on Thursday when it was announced they would be without injured central defenders Titus Bramble and Michael Turner until the New Year at the earliest.
Bramble was due to undergo surgery to repair a damaged knee cartilage today and it was then revealed Turner had damaged knee ligaments when he collided with a post during Monday's 2-2 Premier League draw with Everton and could be sidelined for months.
"It's horrible news," Sunderland manager Steve Bruce told the north-east club's official website. "Michael whacked his knee against the post on Monday and damaged knee ligaments. "He will see a specialist today. I believe it could be months rather than weeks, and that's a big blow to us."
Sunderland have lost just two league games so far this season and only one of those - the 5-1 derby loss to Newcastle - when Bramble and Turner were both in the same side.
"Danny (Welbeck), Darren (Bent) and Asamoah (Gyan) take the plaudits, but in Michael and Titus, we have lost a big partnership who have done very, very well for us.
"I hope the ones who come in can do the job which they have been doing. They will be a big act to follow, I have to tell you."
Sunderland are seventh in the table ahead of their league match away to Wolves on Saturday.