Just hours after completing his move to the Bantams, Clarke played in the first half of City's match at Whitby's Turnbull Ground.
Halifax-born Clarke, who has signed a one-year deal at the Coral Windows Stadium, becomes City's sixth summer signing with just under two weeks to go until the start of the new league season.
City fans can see the FULL interview with Nathan Clarke on Bantams PlayerHD by clicking HERE.