With skipper Carlos Tevez ruled out by a hamstring injury, Mancini must decide whether to include Mario Balotelli, Edin Dzeko or both for the mouthwatering clash.
Micah Richards returns after three weeks out with his own hamstring problem, while David Silva and Nigel de Jong will be included after failing to make the starting line-up for Monday's defeat at Liverpool.
Dimitar Berbatov is set to return for United.
The 22-goal Bulgarian did not even make it off the bench during Tuesday's Champions League triumph over Chelsea, but with Wayne Rooney suspended he seems certain to be recalled by Sir Alex Ferguson.
Jonny Evans serves the final game of a three-match ban, whilst Darren Fletcher is two weeks away from a return after a virus.
Man City (from): Hart, Taylor, Richards, Zabaleta, Kompany, Lescott, Kolarov, Boyata, Wright-Phillips, De Jong, Y Toure, Vieira, Barry, Silva, Milner, A Johnson, Dzeko, Balotelli, Razak, McGivern, Guidetti.
Man Utd (from): Van der Sar, Kuszczak, Rafael, O'Shea, Brown, Ferdinand, Smalling, Vidic, Evra, Fabio, Valencia, Gibson, Anderson, Scholes, Park, Carrick, Giggs, Nani, Berbatov, Hernandez, Owen.