I think when it comes to City's backline,they are always very solid with or without any player.Pep arranged all the different units or wings in the team in such a way that if one player gets injured,there must be another better player to replace him at that position.The only player City have struggled to replace when injured is Rodri,when when was giving a red card,City lost all the three matches to show how important he was on the field.Therefore,his absence will not make them wants to lose because they have quality defenders who can cover in that position, although I know how important he is to the team,but I think they will keep winning games without him.