Wigan manager Roberto Martinez fears Ivan Ramis has suffered a cruciate ligament injury that could end his season.
The Spanish centre-back had to be taken off on a stretcher toward the end of yesterday's draw with Fulham at Craven Cottage.
Ramis appeared to twist his knee in a tackle with Dimitar Berbatov and Martinez expects bad news for the summer signing.
"That is the real negative of the afternoon,'' said the Wigan boss. "I thought Ivan was outstanding throughout the game. I think you are starting to see a centre-half that has adapted to the British game and is someone very, very important.
"I wouldn't want to say anything before seeing the scans, but I fear the worst. He has damaged the ligaments in the right knee and the signs are not great. I expect the worst.''
It was an unfortunate end to a hard-fought encounter, from which Wigan deservedly took a point from.