Sunderland striker Fraizer Campbell is set to undergo an exploratory knee operation that will almost certainly call time on his season.
Campbell first went under the knife after damaging his cruciate ligaments against Manchester City in August, and was preparing to make his return against the same opponents earlier this month when he suffered a setback in training.
It was hoped that rest would solve the new problem, which came after he twisted the knee.
However, he will now have an exploratory operation which is likely to end his season.
Steve Bruce said: "Fraizer is likely to have to go back and see the specialist who operated on him previously.
"He will open the knee up and have a look to see how things are."
Campbell has managed just four appearances this season and his absence has proved particularly costly since Darren Bent's £24million move to Aston Villa in January.
Bruce fears goalkeeper Craig Gordon will also need knee surgery.
The 28-year-old has been an unused substitute for the last five Premier League games after returning early from Scotland duty because of the injury.
Swedish specialist Professor Hakan Alfredson prescribed an exercise programme to help strengthen the ligaments, and Gordon will fly to Scandinavia once again next week to see if that has done the trick.
However, given the fitness concerns which have severely depleted his squad this season, Bruce is pessimistic about the outcome.
He told the club's official website: "Craig sees the specialist next week. He has been following an exercise programme, so we will see what he has to say.
"Given the way the season's going, I wouldn't be surprised to see Craig having an operation too, to be honest. We will have to wait and see."
However, Bruce was hoping for better news on Titus Bramble, who also visited a specialist on Thursday.
The 29-year-old looked certain to miss the rest of the season after damaging a knee cartilage, but the noises coming out of the Stadium of Light in recent days have suggested he might yet play again before the end of the campaign.