Dunga spoke to the press after Brazil's narrow 1-0 victory over South Africa.
"We knew that it would be a difficult match, knowing that South Africa would attack," Dunga told the press after the match.
"South Africa were very quick, the games at the end of a tournament like this are always difficult, but we made it."
Trying not to blow his own trumpet too much, Dunga admitted that sending Alves into the fray was the right decision.
"The play was very closed, so I put in Alves because he is fast and a set piece specialist," he went on.
"Maicon has characteristics to attack, but South Africa made attacking difficult."
Wary of the United States after their shock victory over Spain, the Brazilian gaffer remained respectful to his northern neighbors whilst hailing the performance of his most recent opponents.
"The US has a peculiar way of playing and we will need to stay calm against them," Dunga continued.
"In this form, South Africa's defense will be difficult to penetrate for Spain.
"I did not see the US play last night, but we will now watch the game and prepare for Saturday."
Stephen Crawford, Goal.com
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