Brazil's team doctor Jose Luis Runco said on Sunday that Kaka was not 100 percent fit to play at the World Cup.
Runco said that the playmaker never completely regained his best physical condition following a series of injuries. "In a different situation Kaka wouldn't even play," he said.
Runco said that the Real Madrid midfielder's physical fitness "was at about 85 percent."
The doctor praised Kaka's "dedication" and said he did "all he could" to perform well in the tournament.
Brazil was eliminated by the Netherlands 2-1 in the quarterfinals, and Kaka did not score a goal in the three matches he played.