Derby County defender Craig Forsyth is expected to miss the rest of the season with a cruciate knee ligament injury.
The Scotland international left-back, 26, was taken off on a stretcher after falling awkwardly in the first half of Tuesday's 1-0 win over QPR.
Head coach Paul Clement said: "It was a freak incident. He'll visit the surgeon in the coming days to be assessed. He's set to miss the rest of the season."
Forsyth has made 13 appearances for the Rams this season.
Stephen Warnock is set to play in Friday's Championship match against local rivals Nottingham Forest.