Birmingham skipper Damien Johnson will be out of action for a fortnight after suffering a depressed fracture of the skull.
The Northern Ireland international has undergone surgery after being caught in the face during the first half of Saturday's 1-1 Barclays premier League draw with Fulham.
The midfielder is hoping to be available for the trip to Arsenal on January 12, where he would wear protective headgear.
The injury is the latest in a series of setbacks for Johnson, who missed most of 2007 because of recurring hamstring problems.
Birmingham manager Alex McLeish confirmed: 'Damien took a blow and there was a small fracture. But we believe he could be okay for the Arsenal match by using protective gear.'
Meanwhile, fellow midfielder Mehdi Nafti is refusing to discuss any new contract until the end of the season.
The Tunisia international insists he has had no contact with the club regarding a new deal to replace his current contract, which expires in June.
Nafti said: 'I don't want to talk about it until the end of the season because I haven't had any response from the club.
'For now, I just want to concentrate on Birmingham, then the African (Nations) Cup. I don't want any more questions about my future.'