Ronaldinho was going steadily downhill at the time though. Aguero will be thinking about his career, he'll be thinking, hey, i can start for most of the big teams, so why would i move to Juve when i can move to a team thats already in the CL, that is already competing for titles every season, and that i can actually start for them. Real Madrid being the team in mind here, the only real obstacle is, are Athletico going to sell to Madrid. IMO if Madrid wanted him hard enough, Athleti would sell him to Madrid, yes.