David Silva also misses out at Wembley as Sergio Aguero comes into the starting XI, while Rafa Benitez makes a number of changes after reaching the Europa League final four
The 26-year-old Romania goalkeeper has featured in every round of the FA Cup so far this season and is yet to concede a goal in the competition.
Roberto Mancini makes only one other change to the side that beat Manchester United in the Premier League in their last outing, with Sergio Aguero coming into the starting XI in place of David Silva.
Meanwhile, Rafa Benitez has made a number of changes to the Chelsea side that secured a place in the Europa League semi-finals on Thursday.
Demba Ba replaces Fernando Torres in attack, while John Terry, Frank Lampard, Yossi Benayoun, Nathan Ake and Victor Moses all drop to the bench, and Cesar Azpilicueta and Paulo Ferreira miss out entirely.
Chelsea: Cech; Azpilicueta, Ivanovic, Luiz, Bertrand; Ramires, Mikel; Hazard, Mata, Oscar; Ba.
Subs: Turnbull, Terry, Ake, Lampard, Benayoun, Moses, Torres.
Manchester City: Pantilimon; Zabaleta, Kompany, Nastasic, Clichy; Yaya Toure, Barry; Milner, Tevez, Nasri; Aguero.
Subs: Hart, K Toure, Lescott, Kolarov, Garcia, Sinclair, Dzeko.