The Italy striker picked up an injury in the midweek win over Armenia and may be ruled out of the Rossoneri's upcoming games against Udinese and the Blaugrana
The 23-year-old striker was on target for the Azzurri in the midweek World Cup qualification match against Armenia, but has since returned to his club with a thigh injury, casting doubt on his participation in Saturday's Serie A clash with Udinese and Tuesday's European showdown with the Blaugrana at San Siro.
A statement released on Milan's official website read, "AC Milan announces that Mario Balotelli is suffering from a vastus intermedius muscle injury to the right thigh.
"The player will be monitored in the coming days in order to better define the extent of the problem and determine the prognosis."
Balotelli has scored three Serie A goals in four games so far this season, but missed Milan's last league fixtures after being sent off in the 2-1 home defeat to Napoli in September.