Birmingham manager Chris Hughton has confirmed he is "hopeful, but not overly optimistic" that Nikola Zigic will be available for the game against Portsmouth.
Striker Zigic sustained a knee injury while scoring his fourth goal of the game against Leeds and subsequently missed the weekend stalemate with Southampton but will undergo a late fitness test.
Zigic remains Blues' only injury worry, but Chris Hughton does have some selection headaches as City look to take advantage of their game in hand.
Guirane N'Daw played 90 minutes against Saints despite recently returning from the African Nations Cup, so may be rested.
He could be replaced by either Nathan Redmond or Wade Elliot in a move which could see Jordon Mutch switched back inside to centre-midfield.
Alternatively, Hughton may revert to 4-4-2 and start Adam Rooney, who scored twice in the FA Cup win over Sheffield United.
Stephen Carr was an unused substitute against Leeds but he may have to wait to make his first appearance since picking up a knee injury in December.