Manchester City boss Pep Guardiola does not know if Claudio Bravo will play again this season after the keeper was injured during Thursday's Premier draw with cross-city rivals United.
The 34-year-old, who went off on a stretcher after hurting himself while catching a cross and clearing the ball, was replaced by Willy Caballero.
"Of course he has an injury, probably [out] for some weeks," said Guardiola,
"I don't know if he will be available again this season."
The 0-0 draw - in which Bravo came off after 79 minutes - was only his sixth clean sheet in 22 Premier League games since his £15.4m summer move from Barcelona.