The Bulgaria midfielder has been out with a knee injury since the tie with Sunderland in October.
“It’s difficult to say exactly when I will be fit to play again but I’m making steady progress,” said Petrov.
“With a bit of luck, I should be back early in the New Year.
“I’m hoping to be able to do some running next week and then it will be a case of seeing how things progress.
“If all goes well, I should be in contention for a recall around the time of the Carling Cup semi-finals.
“I just hope the lads do the business (against Birmingham) and make sure we are involved.”
