Kaka arrived in Brazil on Tuesday saying the injuries that kept him from playing several matches with Real Madrid this season will not bother him in next month's World Cup.
The playmaker says he will be fully fit by the time the competition begins June 11.
"The medical team will evaluate my condition, but I'm fine, no problem," Kaka said. "I'll be 100 percent."
A former FIFA player of the year, Kaka endured a groin problem and a thigh injury through parts of season and failed to play at his best.
"It was a tough season for me," Kaka said. "But there is a lot of time until the World Cup for me to get ready. We have examples of players who were not physically fit going into the World Cup but eventually played well, so it's not a concern."
The 28-year-old Kaka was sidelined for 45 days at one point and played sparingly with Real Madrid when he returned.
One of Brazil's doctors, Luiz Rosan, said Kaka is not having problems related to the groin injury, and that the thigh ailment is not major.
Kaka expected to be one of Brazil's main leaders in this year's World Cup, along with Robinho and veteran defenders Juan and Lucio.
Kaka was a member of the Brazil team that won the World Cup in 2002 in South Korea and Japan, and one of the main players when it was eliminated by France in the quarterfinals of the 2006 World Cup in Germany.
Kaka's Brazil teammate Luis Fabiano also arrived in Brazil on Tuesday and also downplayed the injury that is keeping him from playing with Sevilla in the Copa del Rey final on Wednesday.
"It's a minor injury, but I didn't want to risk aggravating it," Fabiano said. "I won't be fully fit by Friday, but in two weeks I should be fine."
Both players will be evaluated and treated at the Sao Paulo club before reporting to Brazil's national team Friday.
Brazil will practice for about a week in the southern Brazilian city of Curitiba before heading to South Africa on May 26. The five-time world champions will play against North Korea, Ivory Coast and Portugal in Group G.