The Brazilian spent six years with Milan and his last club was Sao Paulo.
The 35 year-old told La Gazzetta dello Sport: "When I was at the Sao Paulo and my wife Rebecca was expecting my son, for the first time I realised that going to training was no longer a priority: I wanted to be with her all the time.
"And now that Benjamin is here, I want to watch him grow, not miss a single moment with him. He's a year and a half old and he's already kicking the ball.
"I played my last match almost two years ago, and I don't have much desire to play anymore, even though I consider myself in a transition period, where I'm deciding what to do. I still love football, but my family comes first. "
Asked about becoming a coach in the future, Pato added: "Who knows... I don't think so, or at least that's my current thinking. Maybe as a manager or as a club owner. I've gained a lot of experience in my career, and I can share that with the players. I'd like to do that."