Forward Chris Taylor might have played his last game for Oldham after Tuesday night's 2-0 defeat to Brentford in League One.
Taylor suffered a suspected ankle ligament damage and left the field on a stretcher early in the second half at Griffin Park with a protective splint on his leg before being taken to hospital for a scan and X-rays.
"It looks a bad one," Paul Dickov told Latics' official website.
Taylor, 25, is out of contract in the summer after making 285 appearances for his hometown club.
Oldham chairman Simon Corney has revealed Taylor is "95 per cent certain" to leave the club at the end of the season to pursue his ambition of joining an Championship club.