Blackpool defender Craig Cathcart is facing time on the sidelines.
The centre-half sat out Monday's home game with Huddersfield and was missed as the visitors won 3-1.
Scans on Cathcart's injured calf revealed a torn muscle, and he is now a doubt for Northern Ireland's World Cup qualifier in Portugal on 16 October.
Blackpool boss Ian Holloway told The Gazette: "Any injury is one to worry about. He has a tear in a stabilising muscle in his calf.
"I think he's been terrific for us, as has my whole defence, but we let three in on Monday night so it's back to the drawing board."