Birmingham midfielder Jordan Mutch will face up to three months on the sidelines with a broken ankle.
The 19-year-old suffered the break in a training session last week and will undergo surgery to solve the problem.
Manager Chris Hughton said: "He's a super passer of the ball and that will be a big miss for us.
"These are the unfortunate things you have to work around and of course that will always give someone else an opportunity," he added.
On Tuesday, Hughton moved to sign Senegal midfielder Guirane N'Daw on loan, as cover for the injured Mutch.