Manager Steve Bruce says striker Fraizer Campbell isn't likely to play again this season.
Campbell, who has spent most of the season on the sidelines, twisted his knee in the run-up to the Manchester City game and has been receiving treatment since.
But he is unlikely to return this season, with Bruce admitting the news is a "devastating" blow.
"Fraizer is likely to have to go back and see the specialist who operated on him previously," the manager said.
"He'll open up the knee up and have a look to see how things are."
The former Manchester United frontman hasn't figured in a senior game since damaging his cruciate ligaments in late August.
He has played 40 career games for Sunderland since joining in summer 2009, scoring seven goals.