Poor City, they will have to let Aguero and Cancelo play. IMHO even better options than Walker and Jesus, a little bit unsure about Aguero, he had a big break and he is certainly missing game fitness but he has more than enough class to make it work.
They have to somehow work it out in their absence. Aguero seems very unlikely given he isn't that much fit to start the game. Probably can start from the bench so yeah maybe Pep will have him in his plans for second half maybe.
These are the situations which could propel teams like City and Chelsea on table. They are the teams with longest bench in PL and should be able to overcome missing players with minimal fuss.
Yeah both teams have so much players, so much depth in their squad. Both clubs are full of young talents and experienced players. They have at least one - or two players at each position so yeah they have quite some backup. Could be a problem sometime if backup is also not available. In Sept-Oct, City had no player in centre forward position as both Jesus and Aguero were injured. City were having trouble scoring then so yeah if run out of options then that could be a problem.