The Daily Mail says City launched a frantic worldwide search on Tuesday for a back-up goalkeeper after Claudio Bravo was hurt in training.
The achilles tendon injury suffered by the Chilean has left Pep Guardiola with only one fit senior goalkeeper — first-choice Ederson.
City cannot sign a goalkeeper or take one on loan until January. They could considering applying for special dispensation to sign an understudy, but it is unlikely to be granted.
Despite the transfer window being closed, clubs can still sign out-of-contract players.