Kaka's mother was moved to tears seeing her son again in an AC Milan shirt.
Kaka was presented to the San Siro crowd at half-time in the game with Austria Vienna.
“I almost stole the scene," Simone Leite wrote on Instagram.
"I cried, I had a movie in my head. Life is made up of moments and there are some that you can't forget.
The midfielder is being linked with a director's role with the club.