"In view of a possible call up for the Copa America, I believe that I would not be in the ideal condition to offer the performance expected of me at international level," Kaka wrote in a letter published on Milan's Web site.
"I have not rested for three seasons. With this letter I formally request to be left out of the Copa America."
Kaka, 25, had an exceptional season with AC Milan as he led them to the UEFA Champions League Final and a third spot in the Serie A table despite an 8-point deduction at the beginning of the season. He also spent last summer playing for Brazil at the World Cup 2006.
The Copa America will ruin his off-season at it is scheduled from June 26 to July 15 in Venezuela.
The Selecao coach Carlos Dunga expressed his sadness for missing his playmaker but confirmed that it would be a great opportunity to give the chance for some new faces.