I see that the performance of Manchester City players is quite even in all their lines and indeed they have proven that they do not experience a decline in performance when there is player rotation, the same goes for what will happen in the future, it is true that Kyle Walker is quite an influential player but that doesn't mean that if he is absent then the team's performance will decrease drastically.
Manchester City will face 2 difficult matches in the near future, against Arsenal and against Real Madrid and with the problems they are currently facing, many of their players are injured, even though it is difficult, I think Manchester City still has a big chance of getting through these difficult matches victory.
I believe Man City will soon overcome Walker position, his role is quite vital but cannot completely reduce Man City performance. Pep Guardiola can still cover this gap and balance will be maintained. Against Arsenal, you have to use the correct formation to be really strong, Arteta ambition is very big to try to surpass Pep Guardiola strategy and this time his meeting in fighting for points will definitely result in a heated situation on the field. Apart from that, Man City also needs to be alert because after fighting Arsenal, their players are required to maintain stability. 50:50 of the results of this match will have an impact on the next match, and if another injury occurs then Madrid will really benefit. Therefore, Haaland, De Bruyne and Foden need to play alertly.
Arsenal and Manchester City may be missing some key players and these will be trouble for both of clubs for the upcoming game. I've seen how some Arsenal's attackers were injured like timber, martineli and saka, but I believe Saka will play soon against Manchester City considering that if he has been showing very fast recovery from his injury. Meanwhile, City has been missing some important defenders who effectively helped Manchester City defend from its opponents, such as manchester united, liverpool and other top clubs in the EPL. Some attackers have been rumored injured too like grealish and de bruyne but these guys are back again in the training session expect them to play against arsenal soon.
I don't think you should be concerned because we have Rico Lewis, who can also fill Walker's position. There are also some good players on the bench who can fill in at right back if necessary. This can be anticipated by using a variety of methods.
Manchester City does not have many players who have played as wingbacks, and Pep will take note of this when recruiting new players. The only thing that concerns me is whether Rico Lewis will be able to stop Martinelli if he plays in the upcoming game.
As far as I know, Martinelli has been reported as injured, which is obviously very good news for everyone. I am aware of Martinelli's significant contribution to Arsenal, and this is the main issue that Manchester City must address.