The Premier League champions' nightmare run continued as they collapsed to a 2-1 derby defeat at home to Manchester United on Sunday (15.12.24) and the coach accepted the blame for a loss that leaves them with just one victory in their past 11 matches.
Guardiola told reporters: "I'm the boss, I'm the manager, I have to find solutions but I don't find solutions.
"This is a big club and when you lose eight [out of 11 games] something is wrong. You can say the schedule is tough or the injuries to players, but no.
"I'm the manager and I'm not good enough, simple as that. I have to find a way to talk to them, to train them in the way we need to play, to press the way we need to press.
"I'm not good enough. I'm not doing well. That is the truth."
Guardiola signed a two-year contract extension with City last month and says it is his responsibility to lead the club out of their current turmoil.
The manager said: "I'm here. I'm responsible. It would be easy for me to say we lost because of this action or this player or this situation but football is a team game.
"I'm completely convinced in what I'm saying, that I'm not good enough to find a way for them to feel peace in their bodies and their minds. I want it desperately. I'm here to try and I will try again and again but that is the reality."
He added: "I knew it would be a tough season but I didn't expect so hard."