De Bruyne has been scintillating in 2017-18, registering two goals and half a dozen assists in all competitions with City seemingly destined for a sustained tilt for glory on both the domestic and European fronts.
City themselves are almost perfect in the Premier League, having dropped just two points from their opening eight matches, with De Bruyne at the forefront of a creative hub that has already rattled in 29 goals over that period.
But Guardiola, who enjoyed four trophy-laden years with Messi at Barca, says De Bruyne is not yet at the level of the Argentina forward, and that such comparisons are "impossible".
"The best is just one. If you want Kevin to be considered one of the best he has to win titles. We are here to help him achieve that," Guardiola said in a media conference.
"The best is just one, but he is one of the best.
"It would be a dream for me, I would love all the players – not just Kevin – to achieve the level of Messi.
"I don't want to put the pressure on Kevin's shoulders. He is an amazing player. A humble guy, all his team-mates love him. He wants to play every game and fight until the end.
"But I wouldn't help him comparing to Messi. Messi is apart. He is a guy who scored 60 goals a season.
"I want to help Kevin all I can to get to the highest level possible.
"Many times in the past I've heard: 'That guy's like Messi, that guy's like Messi, that guy's like Messi.' It's impossible."
Raheem Sterling has been one of the beneficiaries of De Bruyne's supply line this season – the England winger is already on to seven for the campaign.
"Kevin is a really great player," he said. "He reads the game really well. He's a massive player to have in your team and for any team in the world he would be a great player."