Martin Paterson could miss the remainder of the season after suffering a second thigh injury.
The Burnley striker has undergone scans on his latest problem and a torn muscle has been identified.
The Northern Ireland international has only recently returned from a three-month spell on the sidelines with a similar ailment.
He came off the bench for Burnley in their meeting with Doncaster last week, but broke down before completing the game.
The Clarets' medical staff believe Paterson is likely to be out of action for at least eight weeks, but manager Eddie Howe fears the absence could be longer.
He told the Lancashire Evening Telegraph: "Pato unfortunately has had a re-occurrence of his thigh injury, which is a huge blow to us."