I am happy that you know that injury can play a major role on the life of a player and a club in their performance. This is why it might be impossible for Man City to win it again next season even with the same players. We saw how injury crippled Man united performance and some other good clubs performance,which made it impossible for them to achieve their goal. Man City was very lucky,that they didnt suffer from injury this season which made the club and players stronger. So let's stop thinking that next season will be the same as this season. Changes is constant,who on earth will believe that Chelsea will perform poorly this season. It is hard to look into the future but we can also think that it is possible for things to remain the way that they are.
I pay enough attention to the strategy that is usually used by Pep Guardiola in every team he coaches, he always tries hard to encourage every player as much as possible to avoid incidents that could potentially become injured and that has proven effective because in the season that has passed, we have not seen the man city player seriously injured (different from other arsenal squad or EPL team)
for now pep guardiola is the best coach in the world who is still active but the fight is not over and we cannot predict with certainty whether man icty will continue to be able to defend the UCL title in the following season.