Ibrahimovic has not started a game since damaging knee ligaments in the Europa League quarter-final clash with Anderlecht in April, but after five substitute appearances this term he finally gets a start for the trip to Ashton Gate.
Henrikh Mkhitaryan is back in the first-team picture but will have to make do with a place on the bench as United start with Rashford, Ibrahimovic and Anthony Martial all in attack.
A capacity crowd is expected at Ashton Gate, with the two teams having not met since the 1979-80 season.
Bristol City: Steele; Wright, Flint, Baker, Magnusson; Brownhill, Smith, Pack, Bryan; Paterson; Reid. Subs: Fielding, Vyner, Kelly, Eliasson, Garita, Lemonheigh-Evans, Taylor.
Manchester United: Romero; Darmian, Lindelof, Rojo, Shaw; Blind, McTominay; Rashford, Pogba, Martial; Ibrahimovic. Subs: J. Pereira, Smalling, Herrera, Mata, Lingard, Mkhitaryan, Lingard.