Their manager, Bobby Robson, has already been forced to rule out Kieron Dyer with a groin injury, and Rob Lee and Jamie McClen are also struggling. With Duncan Ferguson and Temuri Ketsbaia both out, Robson has had to abandon plans to rest his captain, Alan Shearer, for what should have been a formality after their 2-0 first-leg win in Bulgaria.
The former England manager has been desperately trying to bring in new faces during the last three days, but his efforts have so far met with little success. While any new signing would not be able to play in Europe until the new year, he feels that he could do with boosting the size of his injury-hit squad before Sunday's derby with Middlesbrough.
"Kieron Dyer has a slight groin injury and he's not perfectly happy about it," Robson said. "As a result of that, I have made the decision for him and I've taken him out of the squad. He's too valuable to risk."
Silvio Maric, who was not on the trip to Bulgaria after being disciplined for missing a team lunch, is the main candidate to support Shearer, while Paul Robinson may have to make do with a seat on the bench. Alessandro Pistone and Carl Serrant, without a first-team game between them all season, could also be substitutes.