Birmingham's record signing Jota could miss the visit of Preston as he continues to struggle with a hamstring injury.
The forward came off in the 2-0 defeat at Leeds on Tuesday and is a doubt for the weekend.
Che Adams is also having a scan on his own hamstring injury but Isaac Vassell (hamstring) should be back to be in the squad.
Arsenal loanee Carl Jenkinson has undergone an operation on his shoulder and remains sidelined.
Preston are hopeful Daniel Johnson will return in the midlands but face being without Ben Pearson again.
The midfield pair have missed North End's past two fixtures, Johnson having sustained an impact injury in training and Pearson nursing a dead leg, but only the former is in line to make his comeback this weekend.
Boss Alex Neil will also run the rule over right-back Darnell Fisher (groin) after he was withdrawn in the win over Cardiff while John Welsh (calf) may struggle to start again having made just his second appearance in 11 months.
Calum Woods (knee) should be on the bench again having played for the first time since May 2016 in midweek, but Tom Clarke (Achilles), Greg Cunningham (knee) and Declan Rudd (thigh) remain out.