The bad news for Manchester City is about center-back John Stones, it seems this player is not in a good situation he can't play for the team for a long time.
John Stones got injured in the game they had in the Champions League against Young Boys and he could continue the match.
Manchester City is going to have hard games against teams like Leipzig, Liverpool, Tottenham, and Chelsea and they can't have this player which can make everything harder for Pep Guardiola.

Makes sense whenever we emphasize on the need for the managers to improve on the club's squad depth. For a strong club like Manchester City in this season, John Stones who is also an important player in the first XI, should not be the only option they've gotten as a team.
It is obvious that the injury on Stones have left the club in troubles as it was read through the comments of the manager, Pep Guardiola himself. Stones only came back to the pitch in October after he had went off for two months over hip problems. Now he's down again with another injury on his muscles making Pep Guardiola to fear over his absence for another while.
Now, the manager have to face the difficulty of playing a couple of match without Rodri and Stones since both substitutes will be absent from the pitch for a while.
If you watched yesterday's match live, maybe you would only be normal when you saw Chelsea's performance and would not think it was a very strong performance.
But I have enough questions to answer all this, which club can survive with only 9 players? Nothing, even if it's a big club it will definitely lose by a bigger score and that's what happened to Tottenham.
This is absolutely the case of Tottenham and Chelsea yesterday. The misfortune that befall Tottenham was as a result of the two red cards that dropped their first XI squads in the field to nine. The mistake had already been made and the club was to pay for their mistakes by taking the bullet on their foreheads.