As long as there are still replacement players for the line usually occupied by John Stones and Kyle Walker, I don't think Manchester City will immediately become weak because of this. Because the Manchester City coach himself will also think about this more seriously because remembering that the match is at Manchester City's home ground, the Manchester City coach will choose players who are more suitable to fill that line so that the match can be exciting and it won't be easy for Arsenal to win there.
For Kyle Walker and John Stones position I think Manchester City has many option and its not serious problem for Pep Guardiola will make rotation but still solid teams. Manuel Akanji play well as left or right defender and for central forward Manchester City still has Joško Gvardiol will be partner with Ruben Dias. Pep Guardiola is very smart tactician and he can change well with his players from one position to the other position without get much problem and Manchester City has opportunity for taking three points against Arsenal.
As Liverpool fans, wish the match result between Manchester City vs Arsenal must be draw and give advantage has many points left on current standings position. But looks difficult both team will have open play tactician and score as many goal possible to get three points and take opportunity for winning premier league tittle.