The 35-year-old called time on his stint with MLS side Orlando City in October and a return to boyhood club Sao Paulo was thought to be the only option on the table when it came to possibly extending a stellar career.
He also won the 2002 World Cup with Brazil and the Ballon d'Or as best player in the world in 2007.
Kaka, 35, said AC Milan "recently made this proposal".
A devout Christian, Kaka wrote in a Twitter post on Sunday: "Father, it was much more than I could ever [have] imagined. In Jesus name. Amen".
Scooping the Serie A title in the 2003/04 season and the Italian Super Cup in the same year, Kaka would go on to taste heartbreak in the 2005 Champions League final in the iconic Istanbul clash with Liverpool.
Milan and his first team Sao Paulo both offered him a playing contract to extend his career, but Kaka, who was in Brazil's World Cup-winning squad in 2002 and was the last Brazilian to be voted world player of the year in 2007, chose to call it a day.
However, Kaka said his transition off the pitch wasn't being taken for granted. "Just because I have had success as a player it does not mean that I will have it as a Director so I want to take some time out to prepare".