"The goal I scored at Old Trafford was a great moment in my career, like the goal I scored for Italy against Germany in the last Euros," he told City's website.
"As soon as I arrived at City, everyone talked to me about the derby as the game to win and the Old Trafford as the stadium to conquer... I understood that - and did it!
"I am sure me and Nigel (de Jong) will watch the game - perhaps not together - but we will both supporting our ex-teammates, the boss and the supporters big time: we want a win.
"I am sure Roberto Mancini will find the right way to win the derby. I really hope City win."