The midfielder has joined Sassuolo on-loan with the option to sign permanently.
He posted to social media: “THANK YOU - I don't think there's any other way to start this post.
“I want to thank all the people who were close to me, from the workers at Vismara up until those at Milanello, to the drivers who drove me around when I didn't have a licence…
“The staff at Milanello who supported and put up with me at the moments I needed it; the physiotherapists, the doctors, the fitness coaches, the people in the kitchen.
“Thank you to all the fans who celebrated and shouted with me, thanks to all the Coaches who gave their best to help me improve.
“Thank you to my teammates, from my debut with the B team to the first team. A special thank you to President [Silvio] Berlusconi and doctor [Adriano] Galliani.
“And obviously thank you to my family, my girlfriend and my friends who have accompanied me and who will always support me in this new adventure of mine."