Aguero found the net for the third time in the campaign in his side's 2-2 draw with Arsenal, and Pellegrini has urged the Argentine to keep himself fit for the entire season to prove that he is one of the best players in the world.
Pellegrini told reporters: "I think Aguero is among the best players in the world. And I think that now it is up to him to make it and fight for the Ballon d'Or, because he has all the qualities you can ask of a football player.
"He is technically very strong, he is fast and has a lot of power. He is very intelligent, able to play in his position in between midfield and attack.
"And so we hope to see Sergio back in the form he demonstrated in the Premier League before his injuries hit him."
City face Bayern Munich in their first Champions League match of the season on Wednesday.