The 52-year-old has lifted the Premier League four times, while also winning four League Cups and one FA Cup during his remarkably successful seven years in Manchester.
Yet for all his domestic glory with City, it is the Champions League that remains the holy grail.
Guardiola won the Champions League twice as Barcelona boss, in 2009 and 2011, but failed to repeat that success in his three years with Bayern Munich.
City lost to Chelsea in the 2021 final but have also endured a series of agonising exits from the knockout stages, with last season’s astonishing late collapse against Real Madrid in the semi-finals an especially bitter blow.
Asked if his time at City would be judged solely on his European achievements, Guardiola told reporters, “Yes. It doesn’t mean I agree with that but absolutely we will be judged by this competition.”
However, he believes City’s gradual progress from outsiders to established members of Europe’s elite under his leadership deserves more respect.
“Since day one when I arrived, sitting here for the first time, they (the media) asked me, ‘Are you here to win the Champions League?’” he said.
“I said ‘What? If you are manager of Real Madrid maybe I accept that.’ But I accept it here. It’s not going to change.”
City midfielder Kevin De Bruyne is adamant the Guardiola era should still be deemed a success despite the failure so far to land the Champions League title.
“Every year we have been close, quarters, semis, final. We just haven’t done the last bit. We are going to try again,” he said.
“If you care about the noise then obviously it’s going to annoy you. I know we haven’t won it but we have done really well.
“I know people only judge on if you win it, but there have been a lot of circumstances.”
With City trailing five points behind leaders Arsenal in the Premier League, the Champions League is even more important for Guardiola’s team this season.
For City to win the Premier League or Champions League, they will need Erling Haaland at his best.
Haaland scored the penalty winner at Crystal Palace on Saturday to reach 34 goals in all competitions this season.
There are still critics of Haaland’s lack of involvement in City’s build-up play and Guardiola believes the Norway striker can improve that side of his game.
“I don’t like one player just to be in the box to score goals. Of course that is important, it is the main thing, but it is not all we need of him,” Guardiola said.
“When we are away from the opponent’s box he cannot score a goal. We need him to be involved and to be active.
“He has improved a little bit but on this he can do better.”