Balotelli faces fitness race for Milan
Balotelli limped off 12 minutes from the end of the 2-0 victory over LA Galaxy on Wednesday.
Milan says Balotelli has ''a muscular problem in his right thigh'' and will undergo more tests on the team's return to Italy from the United States.
The Italy striker could be a doubt for the Champions League playoff, with the first leg scheduled to take place Aug. 20 or 21. Balotelli is almost certainly out of Wednesday's international friendly against Argentina.