Brazil midfielder Elano is unlikely to play a part in his team's final Group G game against Portugal on Friday due to injury.
The Galatasaray midfielder was injured in his team's 3-1 victory over the Ivory Coast after falling victim to an ugly challenge, causing him to leave the pitch shortly after scoring Brazil's third goal.
Boss Dunga is targeting a win in their final group match against Portugal, despite already being qualified for the last 16 of the World Cup.
Portugal are more-or-less qualified themselves after their 7-0 thrashing of North Korea gave their goal difference superiority over the Ivory Coast, but should they beat Brazil they will overtake them to top the group.
Whatever the situation, the former World Cup winning captain insisted that he would not be tempted to risk Elano, with Dani Alves likely to take his place in midfield.
"We are going to protect Elano," said Dunga. "He might now play tomorrow. But we will wait and see what happens.
"Brazil has to win, otherwise I am going to have tremendous problems.
Play to win
"We have no other option, we play to win, we must play to win. The important thing is we play the best we can."
The five-time champions will also be without Real Madrid playmaker Kaka, who was controversially sent off against the Ivorians for a highly innocuous clash off the ball.
He is expected to be replaced by Julio Baptista, a player Dunga feels can fill the void vacated by the suspended 28-year-old.
"We all know Kaka is a unique player," he said.
"But Julio Baptista has already played in the Copa America with us and he adapts well to going forward.
"Baptista is very powerful and is a good shooter from outside.
"But we have to play as a collective.
"Both Brazil and Portugal have shown their competitiveness over the years. With the quality both teams are able to show, it should be a good game."