Guardiola enjoyed regular success at both Barca and his most recent club, Bayern Munich, winning seven league titles in eight seasons, while also lifting the Champions League twice as manager at the Nou Camp.
City were therefore expected to be serious contenders on all fronts this season after hiring the Spaniard. Instead, they have proven no match for Chelsea in the Premier League title race, while their European aspirations were ended this week by Monaco.
Guardiola was criticised for gambling on an attacking line-up after City surrendered a 5-3 first-leg lead to crash out of Europe on away goals with a 3-1 loss at Monaco in midweek.
It is not the first time Guardiola's methods have come into question with his desire to play out from the back and build intricate attacks coming unstuck at times.
But far from thinking his team selection in Monaco backfired or blaming poor defending, Guardiola felt the defeat was down to players not sticking to the game plan.
For that he himself accepted responsibility, suggesting his instructions were not clear enough, and he is now even more determined to get it right next time.
He said: "I never came here and said we are going to win one title. I never said I am going to win the treble, I never said I was going to win the double. I never said it. I never said it on my first day in Barcelona.
"I promise a lot of work. Few guys can beat me in that. I work a lot. I am so proud of that.
"I never promise titles, never in my life, even when I went to Bayern Munich after they won the treble with Jupp Heynckes. Never. Just work.
"I can only assure (people) they are going to play the way I want. The only power I have is this one. The pleasure is to do the job the way I want.
"The second half in Monaco showed me when you attack more and play more aggressive, you concede few. That game showed me and I am even more convinced what I want to do."