Shot stopper Bravo landed awkwardly after catching a cross in the Manchester derby.
He was replaced by Willy Caballero in the 79th minute.
Bravo had been a spectator for much of the game as United before collapsing on his right leg after leaping.
The 34-year-old has played 29 times for City this season after joining from Barcelona last summer.
Pep Guardiola splashed £15.4m on Bravo – although he has often been criticised for his high profile howlers.
He has been fighting Caballero for the No.1 jersey all season despite failing to earn the hearts of City fans.
Guardiola recently said: “Every week I am going to decide who is in goal. Last week I decided for Claudio.
“It depends on whether the opposition make a lot of high pressing and what I see in the training session. I have confidence in both of them so we will see.”