Balotelli struck a hat-trick in victory over Aston Villa yesterday.
Asked afterwards what he would like for the new year, the City manager said jokingly: "A smile from Mario. That would be great.
"Maybe it could be that he is homesick because he is only 20 years old and it's normal to miss your family at that age.
"My assistant Brian Kidd has told me that Ronaldo had Mario's same problems when he arrived at Manchester United (from Sporting Lisbon) and he needed time to adjust.
"Mario is learning. He has to understand this country and this football before he can give his best. He is working on it, and knows he has to do more for himself as well as for the team.
"When he has assimilated this concept, and made use of his superior qualities, he'll become an important player."