Guardiola rates his former Barcelona star Leo Messi as No1, with De Bruyne close to the Argentine.
Ahead of tonight's clash with Bournemouth, which will be De Bruyne's penultimate in a City shirt, Guardiola was asked if he was the best passing he's seen.
"One is Messi," said Guardiola. "And the other two, let me think about it...OK, let me put Kevin second."
He added: "Messi is the best I have ever seen because Messi has done it really, really close to the box but Kevin is there. It's just the stats, the goals, the assists, that he provides to the team in the final third and the talent.
"That is unique, that is why he has been one of the best players this club has had in the whole history. These are big, big words because he has been a special player."
Man City must move forward
Asked about replacing the Belgian, the manager also said: "There are players who are really, really difficult for many reasons, we know that.
"But the season we have done is the season we have done - we cannot deny it. Of course we have to move forward."