Lee Clark has confirmed that the Blues winger has returned to the club because of fears that he may aggravate an ongoing ankle problem.
"Demarai has returned to us," the Blues boss told the Birmingham Mail.
“It was because of his ankle problem, the one that meant I had to take him off in the Fulham game.
“But this is just more of a precautionary thing and not too serious.
“That was one of the reasons we asked the FA to release him, because he was meant to be going over to play three games, which wouldn’t have been ideal.
“We can work on him now to get him fit and, hopefully, he will be ok for the Bolton Wanderers game.”