The Brazil playmaker is still recovering from a series of niggling injuries which hampered his first season with Real Madrid but Dunga said on Saturday that he expected Kaka to improve as the World Cup wore on.
"We have planned this carefully from both the medical and physical point of view to help him improve," said Dunga, whose team face Ivory Coast in a Group G game on Sunday.
"It was predicted that he would not play for the full 90 minutes against North Korea but the most important thing was to see him in action, and to see him produce those probing runs we know he is capable of.
"I expect he will improve in the next game and, depending on the rhythm of the game, we will see if he can play the full 90 minutes or not.
Kaka was a shadow of his former self in Tuesday's 2-1 win, looking short of confidence and misplacing passes.
Dunga also criticised a Brazilian media report that midfielder Gilberto Silva had an injury problem.
"I'm not going to put out the fire which somebody else started," Dunga told reporters at Soccer City.
"We let you film our practice and you turned it into a circus. Whoever wrote this should apologise to their readers for creating a fantasy.
"You saw that he trained today and you should apologise to the Brazilian supporters."
Dunga also refuted suggestions that he had closed off a Brazil practice on Saturday.
"The practice was one hour and 20 minutes long and it was open for the first hour," he said.
"As coach, I think I'm entitled to have the liberty to have 20 minutes privacy to train free kicks and set pieces. If I didn't have this freedom, then football has to change completely."
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