Crystal Palace manager Roy Hodgson says forward Wilfried Zaha could be out for a long time with a hamstring injury.
Zaha was forced off in the 58th minute of Palace's win over Newcastle on Tuesday, and the 28-year-old will miss Monday's Premier League trip to Leeds.
"We don't know how long it's going to keep him out but he certainly won't be available for this game and it could even be much longer than that," said Hodgson.
"You never know with these hamstring injuries, Wilf is incredible in terms of recovery so I wouldn't want to put a definite timeline on it, but it is a muscle strain and all muscle strains take time to heal."
Ivory Coast international Zaha, who has scored nine goals in all competitions this season, becomes the 10th first-team player in the Eagles' treatment room.
"It is a strange situation," added Hodgson. "From being in a position where we had an awful lot of players available, especially in certain positions, now we are scratching around wondering who could play and fill in for us.
"Our people will be doing their level best to get him back on the field as soon as possible and until then we will miss him because he is a very important figure in our attacking play."
Crystal Palace have been without Wayne Hennessey, Nathan Ferguson, and Connor Wickham for the majority of the season, with Mamadou Sakho, James Tomkins, and Jeffrey Schlupp recently joining them in the physio room.