The Italy striker left San Siro for Liverpool a year ago, but is back on a 12-month loan deal following a disastrous spell at Anfield.
Balotelli is fast running out of chances to get his career back on track, but the 25-year-old has hit the ground running under the guidance of Milan coach Sinisa Mihajlovic.
"He has an extraordinary attitude, he's changed radically," AC Milan CEO Adriano Galliani told Sky Sport Italia.
"He's the first to arrive at Milanello and the last to leave. Mihajlovic often wants the players to have breakfast at 8.30, and he's always there before 8.
"He's probably realised that this is his last chance and I'm sure he won't waste it. His technical ability has never been in question. If he continues with the approach he's had in this first week then he'll be fine."
Balotelli was an unused substitute in Milan's 2-1 win at home to Empoli last week.
