From what I know about Manchester City, Pep Guardiola doesn't rely on one player to win most of his matches. One man doesn't make him win or lose a match because there are many quality players in his squad he can utilize.
Have we forgotten that all this set of players who are not playing to their full potential are players who won last season's PL trophy, that made us think highly of Pep Guardiola for being able to make use of his second eleven to win matches.
This poor performance of Manchester City is a clear indication that the players are all weak, they need some rest to be able to continue again. If it is in the past, how dare Liverpool win Manchester City comfortably without breathing through their nose with the same players they won against today.
It’s a collective effort and the whole players need to step up their game because everyone seem to have lost their form and they are struggling as a team, and as you said it’s the same set of players who won the league last season so they should be able to do the same this season. The players and even the coach seem to have lost his balance and the poor performance means the players and the coach needs to work harder now. I know after the embarrassment Guadiola faced at Anfield he will be even frustrated and channel his anger towards the players and try to bring out the best in them again.