The Nigerian forward missed Saturday's 1-0 defeat at Preston after aggravating a hamstring problem against Reading the previous weekend.
If Utaka is ruled out, David Nugent will continue as the lone striker while boss Steve Cotterill will once again be able to name just four substitutes.
Hayden Mullins will carry on playing through the pain of a knee injury as a makeshift right-back.
Hermann Hreidarsson (Achilles), Danny Webber, Tom Kilbey (both knee) and Billy Goddard (shin) are still on the casualty list while veteran striker Kanu remains unavailable until his contract dispute with the club is resolved.
