The Brazilian forward appears to have put an injury-plagued period behind him and is in line to feature for the Selecao in the country's upcoming friendlies
The 22-year-old striker had returned to action in April after a month on the sidelines, but a new muscular injury forced him to miss the rest of the campaign.
The news comes as a timely boost for the Brazil national team, with Pato included in the Selecao's squad for an upcoming series of friendlies.
"AC Milan would like to announce that that medical tests have shown that Alexandre Pato has made a full recovery from his injury problems," a club statement read.
Pato, who made just 18 official appearances in 2011-12, has been linked with Paris Saint-Germain and Corinthians in recent weeks, but Milan are expected to hold onto the striker in the wake of this news.
The former Internacional player, who cost Milan around €24 million in 2007, will join up with with his country for friendlies against Denmark, the United States, Mexico and Argentina.