Aguero has been with the Cityzens for a decade, but it was officially confirmed last night that the Argentine will be leaving at the end of the campaign when his contract expires.
He is likely to attract interest from several elite clubs, and it is reported that Messi is keen to reunite with his compatriot at the club level for the first time.
Messi has yet to sign a new deal with the Catalan giants, but he is contemplating over an extension after Joan Laporta was elected as the new president for a second spell.
The 33-year-old has still placed some conditions to extend his contract beyond June, and one of those is to sign Aguero on a free transfer this summer.
Aguero has netted a staggering 257 goals in 384 appearances for the Cityzens and he will be firmly remembered as a club legend.
He has obviously had a tough 2020/21 campaign with injuries and coronavirus and lately, he has been out of contention for a starting role.
Hence, it was perfect for both the club and player to part ways, and Aguero may want to test himself with another European club in his career.
A move to Camp Nou will be a tempting prospect for him while a reunion with close friend and compatriot Messi may also be a defining factor.
The La Liga giants have lacked the presence of a genuine striker since the sale of Luis Suarez last summer and Aguero would be a top class signing on a Bosman deal.
He would provide an instant upgrade on Martin Braithwaite and has the chance of leading the line with regularity, which has not been the case this term.
Aguero, who is valued at €25m by Transfermarkt, has bagged just three goals from 14 appearances this term. He has averaged only 32 minutes per game.
Stats from Transfermarkt.es