"I don't know yet, it's difficult to tell," the Birmingham Mail quotes him as saying.
"I don't really want to speculate on it. He won't be coming off if something's just going to be a couple of days.
"He even tried to play on and I am glad he flagged it up very quickly because if it is, indeed, something serious, we don't want any more damage done just because he was trying to get through it there."
Birmingham are 19th in the Championship.