Aguero almost single-handedly revived City’s Champions League hopes on Tuesday with a sensational hat-trick against Bayern Munich.
The prolific Argentina striker scored twice in the last five minutes as City came from behind to beat the 10-man Germans 3-2 in dramatic fashion at the Etihad Stadium.
Aguero has now scored 17 goals this season in 18 appearances, an emphatic return to form after being hampered by injuries in the second part of the last campaign.
Manager Manuel Pellegrini believes he is a potential future Ballon d’Or winner as world player of the year and midfielder Nasri has no doubt he belongs in elite company.
The Frenchman said: “I don’t think I need to speak about his performance — the statistics speak for themselves. He is a great player on his day. He is unstoppable. Last night we needed him and he delivered.
“At the moment he is one of best players in the world. Apart from Cristiano Ronaldo, who is on another planet, he is up there with (Lionel) Messi and (Luis) Suarez.
“He has been unbelievable this year. He was last year as well, the only problem was his injury.
“This year he has been more fit and when he is one on one with the keeper, it doesn’t seem like he will miss the target. He always makes the difference and always delivers for us in difficult moments.”
Thanks to a draw between CSKA Moscow and Roma in the other game in Group E, City had gone into the game knowing that they could not be eliminated whatever the outcome against the Germans.
But had Aguero not produced his late heroics, their prospects of qualifying, with just one game at Roma to play, would have been very slim.
Even now the equation is not straightforward but City know that with a win in the Italian capital in a fortnight they will have a strong chance — if CSKA fail to beat Bayern.
As things stand, Roma, City and CSKA are all locked together on five points.