Derby defender Jay McEveley is facing a spell on the sidelines after suffering a knee injury in the 1-0 defeat to Bolton.
McEveley had to be replaced in the 21st minute at The Reebok Stadium after hurting himself in a challenge with Kevin Davies.
He has been a key player for The Rams this season but early reports suggest he could be out for the rest of the campaign.
It is feared that he has damaged ligaments, although scans will determine later in the week just how serious the problem is.
"It was a bad tackle on one of our main players, said manager Paul Jewell.
Derby have been hit by a number of injuries over the last few weeks and Jewell had just 17 fit players to choose from for the clash at Bolton.