Derby County defender John Brayford has been ruled out for about six weeks with a thigh injury.
The Rams right-back, 24, suffered the injury during the 4-0 defeat against Southampton on Saturday and had to be substituted after 58 minutes.
Manager Nigel Clough told BBC Radio Derby: "It doesn't look too promising.
"If it's six weeks, which is the norm for this type of injury then it puts us quite close to the end of the season. It's a big blow."