The 22-year-old Italian completed a £19m move to the Serie A side on 31 January from Manchester City and made an immediate impact with two goals on his debut against Udinese.
But Balotelli, rarely out of the headlines during a two-year spell at City, has been subjected to racist remarks from the brother of the former Italian prime minister and Milan owner Silvio Berlusconi.
The incident took place over the weekend just hours ahead of Balotelli's Milan debut.
Paolo Berlusconi said: "I've finished. OK, we are all off to see the family's little ******. He's a madhead. All the young ladies are invited as well - you can even have a chance to meet the president."
The 64-year-old newspaper boss was attending a political rally in Monza for the People of Freedom Party when he made the remarks on stage before heading to the San Siro to watch the match which ended 2-1 to the hosts.
The incident was filmed by local reporters and is being shown on the website of Italian newspaper La Repubblica.
The comments come just a month after AC Milan players walked off during a friendly match in protest to racial abuse from the crowd directed at Kevin Prince Boateng.
At the time, Silvio Berlusconi praised the players for their behaviour and said there should be a zero tolerance policy against racisim.
City signed Balotelli from Inter Milan for £24m in 2010 and he scored 30 goals in 80 appearances for the club, although he only managed three goals in 20 matches in the current Premier League campaign.