Blues goalkeeper Colin Doyle underwent a minor knee operation earlier this week.
The 23-year-old Irishman went under the knife on Monday to remove a small part of cartilage and is likely to be out of action for approximately two weeks.
The operation has come at the perfect time with the Championship taking a fortnight's break due to internationals.
But Doyle could still be a doubt for Blues' next game at home to Doncaster Rovers a week on Saturday.
The good news is that third choice keeper Artur Krysiak is back in training following his dislocated finger injury picked up during his recent loan stint at York.
And the young Pole should be fit to take his place on the bench as the deputy keeper for Rovers' visit, should Doyle not recover in time.