The midfielder injured his foot in AC Milan's win over Siena earlier this month, his first game following a month out with a similar problem.

The Brazilian Football Confederation revealed on Tuesday they had received positive results from medical tests but the team doctor remains pessimistic ahead of the match at the Olimpico Atahualpa this weekend.

"There was progress because Kaka trained on the field and we are watching him every day to see how he is," said Runco.

"If the match was being played today, he would not be able to play. He is not ready physically yet."

Kaka, however, is optimistic.

"I trained well," he said. "I am quite happy and hopeful I will play.

"We'll talk to the medical staff to see how the injury is reacting, whether I will feel any pain. I have not felt anything during the whole training session."

After the trip to Ecuador Brazil face Peru in Porto Alegre.