In his three years working under Guardiola, Sterling has emerged as one of City’s most influential players, a fact also recognised by his peers who voted him as the PFA Young Player of the Year last season.
The 24-year-old has carried on that stunning form so far this term and was also at his mesmeric best for England in the Three Lions' two Euro 2020 qualifiers earlier this month, scoring in the wins over Bulgaria and Kosovo.
That quality and consistency has led several pundits and observers to tip Sterling as a potential future Ballon d’Or winner.
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However, quizzed at his Norwich pre-match press conference, Guardiola said that Sterling wasn’t yet at the exalted level of Messi or Ronaldo.
But the City boss added he had no doubts Sterling possessed both the raw talent and necessary application to go on and potentially join the world's elite players.
“Right now no, but maybe in the future, I wish for it,” said Guardiola.
“They (Ronaldo and Messi) scored 50 or 60 goals a season in the last decade, and have won the Ballon d'Or and prizes every year except this one… they are legends, something unique in world football.
“If Raheem can target that level, wow.
“Of course, he can do it and I won’t be the guy to tell him his limits… I want him to practice after training.
“But right now, nobody – at any club - can compare with these two guys what they do every week for a decade. Nobody can compare.”
Asked whether he had dedicated any change in Sterling since he started working with him in the summer of 2016, the boss paid tribute to Raheem’s relentless quest to improve and progress.
And he said that was evidenced by Sterling’s clinical quality in front of goal – a development which saw him score 25 goals last term and already claim six goals in five appearances for City this term.
“It is his talent and desire,” Guardiola added.
“With Brendan Rodgers too (at Liverpool) he played well and also for the national team.
“Since the beginning he has had an incredible mentality to get better and be more clinical, and he’s a winning player now.
“Sometimes before he made good dribbling action but not the finish, now he can win games by himself.
“Always it’s practice and practice and practice and mentality.
“The guys who score goals are in front of the goal, you cannot score goals when you aren't in those positions. Now he is.”