Yeah, I guess the lackluster performances this season started from the manager. I can't find some of his past interviews but it came across to me as he's lacking the motivation or that he's looking for a new challenge. It's something similar to when he was winning it all at Barcelona.
I think that Guardiola wasn't having everything this season. At some point in his life, there was matrimonial issues, equally the team were not putting everything together. I guess no matter what coach teach the team, if they don't put there mind to deliver it, there is no way it will yield anything at the end of the day.
This time, there wasn't significant changes in players but we are going to find out by next season. If the there is sold off players and there is improvement from players, that means the players are the one at fault and if there is not, then Guardiola is at fault here.