USA defender Jonathan Spector will be out for at least the next three month with a torn right thigh muscle and a tendon injury, the team announced.
Spector, who plays also plays for Birmingham City in the Football League Championship, was injured during a match against Millwall last weekend.
Spector has made 10 appearances, with eight starts this season for Birmingham City, who is in 20th place out of 24 teams.
"Jonathan Spector will be out for at least three months. He’s torn a thigh muscle and a tendon," Birmingham manager Lee Clark said. "I think it’s a very similar injury to the one he had the season before I got here on the other side."
The club also announced that Demarai Gray has returned to training and should be able to play against Charlton Athletic on Saturday.
- Scooby Axson