Matt Clarke is likely to be out of action until the end of the month.
The big centre half has missed the last three City games with a training-ground injury to a medial ligament.
And Stuart McCall is resigned to losing him for longer as Clarke has failed to respond to treatment.
McCall admitted: "We think it's going to be a few more weeks yet, which is bad news.
"He went to block a cross from Joe Colbeck in a practice game and at first we just thought he'd tweaked it but it's not responding as well as we expected."
Loan youngster TJ Moncur has filled the gap alongside David Wetherall but McCall feels his best position could be as a right back.
"He has played both at Fulham and is obviously comfortable on the ball," added McCall.
"In this day and age pace is a big thing. That's probably an area we've lacked a little bit and he's got us out of trouble.
"Maybe full back is his stronger position."
Mark Bower, who has not featured in a game in 2008, is close to coming back from his knee injury.
McCall said: "He just needs a lot of football under his belt now because he has missed so much."
- Start or join a debate on this issue in our online forum - Click here
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article