Assombalonga, Mkandawire and Smith come back inPaul Sturrock made three changes to the Blues side that beat Bury in the FA Cup second round on Tuesday night for the visit of Bradford City in League 2.
Paul Smith returned in goal despite the heroics of Daniel Bentley in Tuesday's penalty shootout.
Britt Assombalonga and Tamika Mkandawire, who were both ineligible on Tuesday came into the side for Barry Corr and David Martin respectively.
Ryan Leonard was back among the substitutes following injury.
Blues: Smith; Clohessy, Cresswell, Prosser, Barker; Hurst, Mkandawire, Laird, Timlin; Assombalonga, Tomlin. Subs: Straker, Eastwood, Corr, Martin, Donnelly, Bentley, Leonard.