Jonathan Grounds is a doubt for Birmingham when they host Cardiff on Friday, live on Sky Sports as part of the Sky Bet Football League's 10 in 10.
The defender suffered what boss Gary Rowett described as a "little knock" in Tuesday's 1-1 draw at Preston.
David Cotterill (knee) and Paul Robinson (thigh) were due to return to training on Thursday but neither will be fit to face Cardiff.
Striker Clayton Donaldson (groin) remains out but the club are hopeful he could make a comeback over Christmas.
Cardiff manager Russell Slade hopes to name an unchanged team after the Bluebirds' last-gasp 3-2 win over Brentford on Tuesday night.
Slade reported "one or two little problems" after the midweek victory and must wait to see if the short turnaround scuppers his plan to send out the same side at St Andrew's.
Kenwyne Jones and on-loan Tony Watt came up with the goals against Brentford and Slade will want the strike pair to continue their blossoming partnership after starting the last four games together.
Five-goal Joe Mason, who has made way in recent weeks, is fit to take his place on the bench after being troubled by a virus and a sore back.
Watch Birmingham v Cardiff in the Sky Bet Championship, live on Sky Sports 1 HD on Friday night from 7pm.