Balotelli joined City from Inter Milan in the summer of 2010, but there have been persistent reports of homesickness and numerous links to clubs in Italy.
However, the forward has recently suggested he is adapting to life in England - "If last year I missed home so much, maybe now I miss it a little bit less," he said last month - and Mancini hopes he will remain at Eastlands for many years to come.
"Sooner or later, Balotelli will go back to Italy," he told Corriere della Sera on Tuesday. "That is for sure. However, it won't happen for a few more years and it will do him good to remain at Manchester City for the time being.
"We did receive various offers for him from Italian clubs over the summer, but we don't sell anybody here."
Balotelli could make his Champions League debut for City on Wednesday night when they travel to Villarreal having completed the suspension he carried over from last season's Europa League. As a member of the Inter squad crowned champions of Europe in 2010, Mancini feels Balotelli has much to offer the side.
"Mario could be an important player for us in Europe because he knows the Champions League," he said. "It's an important competition for Mario, because it's the first game back for him after his ban."
He added: "For the supporters, Mario is an important player, an important guy, and for the last two months Mario has been more serious. He's trained very well. I hope he can continue like this but I don't know whether it's possible.
"He scored two goals in the derby, he is scoring in every game. As a player he is fantastic and for the supporters that is what matters."