كتب : وكالات
"The Italian's injury is to the lateral meniscus, one of the two most crucial structures in the knee," read a Statement carried by City's website.
"Medical wisdom is to try and encourage the problem to heal without recourse to an operation.
"It was hoped that the symptoms would settle down but once Balotelli began to step up his recovery program this week, it became clear that action would need to be taken."
The 23-year-old forward has sustained the injury on his debut against FC Timisoara in the Europa League.
City signed Balotelli from Inter Milan this summer for £23 million.
Manager Roberto Mancini hoped to name Balotelli against Blackburn Rovers on Saturday before his lay-off was confirmed.