"In this competition you need something special, and still I don't feel it,” Guardiola said on the eve of his side's game against Shakhtar Donetsk.
His comments were in part designed to stir up a reaction from the City fans, who have never fully taken to UEFA and its flagship competition, but he also believes his young side's lack of experience at the highest European level will count against them.
When you consider that a team with either Cristiano Ronaldo or Lionel Messi has won each of the last five Champions Leagues, you feel he may have a point.
Yet it is Pep's side that are favourites this season and, after their shock opening round defeat to Lyon, they have finally arrived in Europe this season.
Such was the English champions' dominance over Shakhtar that the Ukrainian fans resorted to a Mexican wave on the hour-mark. It was 2-0 to the visitors by that point and it could have been so much more.
In the end it was three, after Bernardo Silva came on to succeed where some of his team-mates failed; while others slashed at their chances, he kept a cool head to put the game to bed with a precise finish from the edge of the box.
David SIlva had got the ball rolling in similar circumstances half an hour in, delivering the goal that City's blistering start deserved. The Blues probed the hosts from all angles, but with Riyad Mahrez and Gabriel Jesus looking particularly wasteful, a goal eluded them until one of their cool-headed midfielders got a sight of goal.
City could have added a couple more before Aymeric Laporte – perhaps the Blues' most reliable performer this season – headed in the second.
Had Jesus, Mahrez and to a lesser extent Sterling had their shooting boots on this could have been six or seven. Either way, it is enough to put them back on top of Group F, just two games after that surprise home defeat against Lyon.
Guardiola may not believe his team are ready to win the big prize but he certainly rates them; he also said on Monday that the first 45 minutes against the French side was their only dip in form this season.
They were sluggish and deservedly beaten that night but they have been better since, even if they needed a late comeback to get back on track at Hoffenheim last time out.
And on the evidence on Tuesday night they are certainly up and running now.
No English side had previously won here and this was perhaps City's best performance of the season, in any competition. Not bad when you consider they are top of the Premier League, having scored 26 goals in nine games, and came within a missed penalty from beat Liverpool, their supposed bete noir .
Also consider that this most polished of performances came with Leroy Sane, Sergio Aguero, Bernardo Silva and Kyle Walker on the bench.
The only thing you could really hold against them is that they were not as clinical as they could have been, and while that will need to be improved the further they go in this competition, it is hardly the biggest concern in the world right now.
Not when you consider the defeat to Lyon, and the concerns that brought about City's vulnerability to being pressed, to being 'got at'. Hoffenheim tried it but could not keep it up; Shakhtar simply could not get the ball.
The Ukrainians travel to the Etihad Stadium in a fortnight's time and they will hardly relish the prospect. Neither will many other sides around Europe.