The Napoli central midfielder was Guardiola's no1 target for the summer, as he tries to improve a squad that managed 100 points in the Premier League.
But he does not believe the player was sufficiently committed to signing for City, given his last minute move to Chelsea instead.
"No, I'm not disappointed," he said during his press conference.
"We tried, but at the end all my advice for the players is that they have to go where they want to go.
"For the guy, it would have been a mistake for him and for us if he had decided to come here when he wanted to go with Maurizio and Chelsea.
"So it is important that English football has received an exceptional player and at the end if they want to come, it's better they come.
"If he decides to go to Chelsea for the reasons he has explained or will explain, then all the best for him."