Messi and the Manchester City striker have long been close friends, with the duo being part of the Argentina set-up since their youth.
The Albiceleste captain is believed to hold sway over transfer dealings at the Camp Nou, and speculation in the past has suggested that he could end up playing alongside Aguero for the same club at some stage.
But Bartomeu insists his star player has never made such a request and denied that the 27-year-old has a say in who Barca sign.
When asked by Radiogaceta “how many times has Messi asked for the signing of ‘El Kun’ [Aguero],” Bartomeu replied: “No, he has never asked us.
“Kun Aguero is a great player, he has a contract with City, and we have a lot of respect for players with a contract. Messi does not ask for signings.”