Birmingham not only crashed out of the Carling Cup 3-0 at Blackburn but had goalkeeper Richard Kingson taken to hospital just on half time after he accidentally collided with Rovers centre back Chris Samba and the post as they challenged for a David Bentley free kick.
After receiving lengthy treatment the Ghana stopper was helped to his feet but then immediately collapsed and was stretchered off.
Blues boss Steve Bruce said, "We don't know how he is just yet. He is in hospital and it would be wrong to speculate but it is a head injury. He is conscious but at least he is in the right place.
"It was horrible; no one wants to see serious injuries but the reports seem to indicate it's nothing serious."