Kaka, who missed Sunday's La Liga game at Malaga with a hamstring problem, said he would spend four days at Brazilian club Sao Paulo for physical reconditioning before Brazil assemble for a pre-World Cup training camp on Friday in Curitiba.
"I'm going to Sao Paulo to be evaluated, they will see my condition and that I won't have any problems," he told reporters.
"I will be 100 percent by the World Cup," added Kaka who was also sidelined for six weeks in March and April.
He had a frustrating first season at Real Madrid, failing to find his best form while his team were knocked out in the last 16 of the Champions League and saw arch-rivals Barcelona walk off with the league title.
"It was a very difficult season which I had, but we have examples of players who were not in good form before the World Cup and ended up doing well, so I'm not worried," he said.
Five-times champions Brazil face North Korea, Ivory Coast and Portugal in their first round group at the month-long World Cup finals, which start on June 11.
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