Aguero and Messi have been close since they were teenagers, when they came through the ranks of Argentina's youth teams, but have never played together at club level despite both men thriving in European football.
It has been reported on several occasions this season that Messi would be open to moving to the Premier League, with City actively pursuing his services, and Goal understands the Etihad Stadium would be his most likely destination should he ever decide to leave Camp Nou.
Messi is unhappy with his ongoing tax case in Spain, something which is said to play a big role in any decision on his future, but Aguero believes his countryman is happy enough in his current surroundings to stay at Barca and spurn any advances from other clubs.
"If he wants to come here, let him come!" Aguero told Goal.
But he warned that any potential suitors are likely to be left disappointed: "It's very difficult for Leo to leave Barcelona, because he’s played there since he was very young and it’s not easy for him to think about another team," he added, to Omnisport.
"So no… hopefully he can be here at City obviously, but of course it’s always the player’s decision and I think he’s very comfortable and very calm in Barcelona."
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Following those reports that Messi could be set to move to the Premier League, many wondered whether the four-time Ballon d'Or winner would be able to replicate his best form in English football.
Messi has been key to Barcelona's recent successes - since 2008 he has won five league titles and the Champions League three times - and Aguero does not believe he would have any trouble showing his quality in any surroundings.
"He’s the best in the world, he can handle the Chinese league too! Because he’s the best in the world there’s always pressure in any country. If you’re the best player in the world you can be the best anywhere."