Manchester City suffered heavily last season, one of the reasons was the absence of Rodri and it added up to their poor performance last season but I believe they have made provisions for that position. I also believe without Rodri Manchester City can still be a strong team they cannot depend on him forever.
True they can't depend on him forever but is really bad to make your team be strong because of one player, it will definitely back fire. Rodri's absence made other clubs to see Manchester City as a small club that they can joke with, honestly last season wasn't what I expected of Manchester City and Pep Guardiola as well, everything he tried to build went offline and it was as if he had no idea on what to do next. Now same incident with the same player, I think is time to take that bold step and forget about Rodri and get somebody to take that spot if not they're going to continue with the struggle of last campaign.
Manchester City really suffered last season, and to be honest, I wasn’t expecting them to be that bad last season, but unfortunately, they did not perform well last season, and it was so disappointing. Although, as you said, you are right; depending on one single player or two in a squad is really a mess, and I feel like it is among the reasons why Manchester City was affected. I just hope they will get back stronger next season because if Manchester City experiences the same thing as last season, it won’t be funny at all.
City will definitely be strong next season depending on how they amend the positions that was covered by some of their best players who left like Walker, KDB and this very player Rodri although his case is base on injury and I won't include Grealish because he has never contributed anything to the club since he arrived. If we use the way Manchester City performed last season to judge them this season it will be very wrong because the players they have now are having that hunger to start the season which I believe they will dominate very well against teams that made a mess out of them and their next opponent will feel their wrath.
My problem is that Rodri's position that has been causing problems whenever he's not active, Pep need to work more on the former Chelsea guy Mateo Kovačić because he's the only play in that team that can try to play that position that's if Pep Guardiola isn't planning on getting a replacement for Rodri and they'll excel more better than they did last campaign.