Sterling, who scored 17 goals with ten assists last season, has picked up where he left off in the Premier League with Manchester City this term with 5 goals in four appearances so far.
And being pivotal for both club and country, Guardiola believes the 24-year-old has the qualities to meet the benchmark set by the two football greats.
"Right now he is not in that level, I wish maybe in the future," Guardiola siad in a news conference.
"It would be a dream for him, for all of us and for him, but right now these two guys the last decade have scored 50, 60 goals every season and I don't know how many assists.
"They have won the Ballon d'Or and all the individual prizes every single season, except maybe last season.
"So the consistency of these two guys – they are legends, they are something unique in world football. And if Raheem can target that level, wow.
"We will be here to help him and of course he can do it, I will not be the guy to say don't think about that. No, absolutely not, I want it.
"But right now, nobody, not in this club but in all the clubs in the world, nobody can compare to what they have done every single week for 10 years. They [Messi and Ronaldo] are absolute legends and nobody can compare, nobody."
Manchester City, who look to retain the Premier League title for the third time will be hosted by Daniel Farke’s Norwich City at the Carrow Road as Finnish striker Teemu Pukki will hope to continue his scoring streak.
The Citizens are second in the table with ten points, two points adrift table-toppers Liverpool after four games thus far.
