Atletico Madrid president Enrique Cerezo has claimed the manner in which Sergio Aguero left the club was 'stupid'.
Aguero joined Manchester City in 2011 in a deal worth £38m, leaving Atletico after scoring 101 goals in all competitions for the La Liga side.
He won the Europa League and the UEFA Super Cup during his spell with the Vicente Calderon Stadium club, but Aguero has since established himself as one of the best strikers in the world with Manchester City.
The Argentina international has scored 113 Premier League goals for the Citizens, but Cerezo still harbours some resentment over the way he left the club.
"He (Aguero) has been the only player who left Atleti under a cloud, as he was stupid," Cerezo told Cadena Cope's El Partidazo show, as quoted byFootball-Espana.
"He arrived as a hero, and he left through the back door.�
There has been speculation in recent weeks that Aguero could leave Manchester City, having been dropped for teenager Gabriel Jesus, and Atletico havebeen touted as a potential destination for the 28-year-old.
Aguero has scored 11 Premier League goals this season, but his recent performances have come in for criticism, with the striker without a goal since early January.
Manchester City are currently third in the league after beating Swansea 2-1 on Sunday, during which they were saved by Jesus' late strike after Gylfi Sigurdsson had equalised late on.
Aguero will hope to return to City's starting team when they face Bournemouth on Monday.