Crystal Palace manager Roy Hodgson has rued the injury picked by Bakary Sako in their 1-1 draw with West Ham United.
The Mali international limped off in the first half of the English Premier League tie and could be out of action for a long period.
“We won’t know how bad it is until tomorrow but my medical staff and sports scientists are very good and have an unerring knack at being right with their initial prognosis, and they aren’t very optimistic – they don’t think it’s very good at all,” Hodgson told club website.
“The positivity of getting a point here is offset by paying such a high price if Bakary Sako is now going to miss a large part of the season, simply because we don’t really have the luxury of losing a forward player because we are so short in that area.