Joseph Yobo is struggling with a hamstring injury and admits he is uncertain as to how long he will be out.
The Everton centre-half, who is currently away on international duty with Nigeria, has been struggling with the complaint for the best part of a week.
The problem has blighted his African Cup of Nations campaign so far, with his involvement in the remainder of the competition now in doubt.
Yobo has been in regular contact with his country's medical staff throughout his time in Angola, though, and is hoping the injury is not as bad as first feared.
He admits he will definitely sit out Nigeria's clash with Mozambique on Wednesday, but insists he could be ready for action in time for the quarter-finals - should the Super Eagles make the last eight.
"I am not feeling 100 per cent, that is for sure," Yobo told skysports.com.
"Being out of the African Cup of Nations is another thing though.
"I will miss the next game, that is for sure, and we have not qualified yet, so maybe I will not play again."