Wigan midfielder James McArthur's injury problems are becoming an increasing worry for manager Roberto Martinez.
McArthur, 25, has missed two games with a dead leg, and the injury shows no sign of improving.
The Scotland international picked up the injury in training just before the 1-0 win at Tottenham on November 3, and sat out the weekend's 2-1 defeat at home to West Brom. He faces a struggle to be ready for Saturday's trip to Liverpool.
Martinez told the Wigan Evening Post he was not sure when McArthur would be fit again, explaining: "It's hard to tell, because we expected James to be fully fit for the West Brom game and it was disappointing to see him miss out.
"His dead leg is worse than we originally thought, and already we are looking at Thursday or probably Friday before we'll know if he'll be OK for Liverpool."
Martinez also has a minor injury concern over goalkeeper Ali Al-Habsi, who damaged his shoulder in the warm-up before the West Brom game but managed to get through the full 90 minutes.
Al-Habsi has reported for international duty with Oman and will be assessed ahead of their World Cup qualifier against Japan on Wednesday.
"Ali picked up a little knock in his shoulder and we were concerned before the game," Martinez said. "He was able to play, and now we can assess his situation."