The Italian's departure came a few weeks after a training ground spat with Mancini.
"In a training session, I said to players not to make stupid tackles on Gael [Clichy] because he was just coming back from injury. And then, Mario made a strong tackle on him. I was furious," Mancini told L'Equipe.
"I grabbed him by the collar wanting to push him but he is so strong physically I couldn't move him. From seeing the pictures, you would think that we came to blows but nothing happened.
"He came into conflict with some team-mates because of his behaviour, and he wanted to return to Italy. I was disappointed that he wanted to leave because he should have done so much more in an extraordinary championship."