Birmingham manager Alex McLeish: "Stephen has been playing with a broken toe and been having injections to help him get through the games so far.
"I can tell you that is not nice but it also shows the type of character that he is.
"The good thing is he will get a decent rest after tomorrow's game because of the two-week international break and that should benefit him."
The former Newcastle player hung up his boots in 2008 but McLeish persuaded him to sign for Birmingham.