 Before the start of the new season, Pato switched to the squad number 9, as Filippo Inzaghi had retired at the end of the 2011–12 season.In the third training session of the season, he injured his thigh and was kept out for the first six weeks of the new season.On 21 October 2012, Pato made his return to Milan, in which he assisted Stephan El Shaarawy for the second goal in a 3–2 away defeat to Lazio.