The 23-year-old returned to Italy in January 2013 but has apparently become disillusioned with life at the Rossoneri, who are 11th in the Serie A table.
Chelsea and Arsenal are reportedly considering bringing the former Manchester City striker back to the Premier League in the summer, but Galliani has insisted that Balotelli's relationship with the club is healthy.
"He has never felt badly here," Galliani told reporters. "I repeat, some people forget how much he helped us last season achieving Champions League qualification.
"He's been here a year and two months and he has a really high efficiency that is liked by the club."
Balotelli has scored 27 goals in 80 appearances for Milan in all competitions.