Darren Ferguson, manager of Doncaster Rovers
Ferguson has gone from not being listed at all to joint-fifth favourite for the role at 10/1 - alongside Alan Pardew, Nigel Adkins and Quique Sanchez Flores.
The Scot led Doncaster to promotion last season, but saw his side beaten at home to Shrewsbury Town on Tuesday, leaving them 18th in League One.
He had been linked with the Oldham Athletic job, only for Doncaster to deny those rumours earlier this week.
However, the chance to return to the Championship with Birmingham could appeal to Ferguson, whose father, Sir Alex, is the legendary ex-Manchester United manager.
Graham Potter, the Ostersunds head coach
Another new name on Sky Bet's list of possible appointments is Ostersunds boss Graham Potter, who is now 16/1.
The 42-year-old was born in Solihull and played for Birmingham in the early 1990s, but has been managing Ostersunds - with whom he won the Swedish Cup earlier this year - since 2011.
Aitor Karanka (6/4) continues to lead the betting, ahead of Steve McClaren (7/2), Lee Carsley (9/2) and Steve Cotterilll (5/1).
Would Ferguson be a good appointment for Birmingham?