Birmingham defender Martin Jiranek has undergone a toe operation and is rated doubtful for Saturday's home Barclays Premier League clash with Bolton.
The Czech Republic international has been defying the problem to continue playing for several weeks but had to be substituted in the early stages of City's last game at Wigan.
Birmingham manager Alex McLeish confirmed: "Jiranek had a minor operation on his toe. He has been playing with that discomfort for the past eight to 10 weeks. We had to do something about it."
He added: "He came off after 15 minutes of the Wigan game. He was clearly in distress and also being restricted in his running. He is a doubt at the moment for the weekend."
City's injury problems are easing with key midfielder Lee Bowyer back in contention after a hamstring injury.
The former England midfielder has resumed training.
Leading scorer Nikola Zigic will also be available after a groin problem to face the Trotters after playing for Serbia in midweek as a substitute.
McLeish said: "Zigic played 15 minutes for Serbia, coming off the bench, and that indicates he is fit and ready to play.
"He has been out for a couple of weeks. Whether he can start the game, we will have a look at it over the next couple of days."
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