Huntington is expected back after a hamstring injury, while Earl has trained this week, having recovered from a knee problem.
Calum Woods, however, has a calf strain and is unlikely to be fit and Darnell Fisher is also a doubt with a hip injury.
The game is likely to come too soon as well for Louis Moult, who is close to overcoming a hamstring complaint.
Tommy Spurr and Sean Maguire remain sidelined with knee and hamstring injuries respectively.
Birmingham boss Steve Cotterill has one new injury problem following last week’s home defeat to Derby, but would not name the player.
Goalkeeper Tomasz Kuszczak will return to contention after missing out for several weeks with a groin injury.
Otherwise, Cotterill is expected to choose from an unchanged squad as his side bids to climb out of the bottom three.
Newcastle have been linked with a shock move for former Sunderland goalkeeper Simon Mignolet during the summer.