Already through to the next stage of the World Cup, Brazil wants to keep its momentum going into the round of 16 by beating Portugal on Friday.
A win would also allow Brazil to finish first in Group G, possibly avoiding a match against European champion Spain in the next round.
Brazil can finish first even with a draw in Durban. The team leads the group with six points, two more than Portugal, which virtually clinched a second-round spot after defeating North Korea 7-0. Ivory Coast has one point and the Koreans zero.
"Brazil needs to go into the match thinking about winning it," said Kaka, who will not play after being sent off against Ivory Coast. "It's fundamental to finish first. We know a draw will be enough, but winning will be important to give us confidence and motivation for the round of 16. Brazil will try to win this match."
A victory also would allow Brazil to play the second-round match in Johannesburg, where it has been training since arriving in South Africa last month. The second-place team will have to travel to Cape Town for the round of 16.
"Our goal is to keep playing better during the competition," Brazil captain Lucio said. "We need to use this match to try to fix the mistakes we have made, to be prepared for the decisive stages."
Brazil began its quest for a sixth world title with a difficult 2-1 win over North Korea at Ellis Park, struggling to break through the tough defending of the Asian nation. Brazil played better in the second match, beating Ivory Coast 3-1 at Soccer City.
"It's important for the team to keep improving as the tournament goes on," coach Dunga said. "It's what we want to happen."
In addition to not having Kaka, Brazil may also be without starting midfielder Elano, who is nursing a right ankle injury. Doctors have said he will be fit, but Elano trained separately from the group for the second day in a row on Wednesday.
Brazil and Portugal are deeply connected nations. They are the only Portuguese-speaking countries at the World Cup, and Portugal enters the tournament with three Brazil-born players—Deco, Liedson and Pepe.
The teams have played two friendlies since the 2006 World Cup in Germany, with Portugal winning 2-0 in 2007 in London and Brazil coming out victorious 6-2 a year later in Brasilia, Brazil's capital.
"There is always a rivalry between Brazil and Portugal," Kaka said. "It was one of the teams we played the most in the last few years."
The group winner could avoid another high-profile match in the next round if Spain tops Group H. That group is wide open, however, with Chile, Spain and Switzerland all with a good chance to advance.
Chile currently leads the group with six points, followed by Spain and Switzerland with three each. Honduras has zero points. Spain will face Chile in the last match and Switzerland plays Honduras.
"It's a very equal group, we've been taking a close look at all the matches," Kaka said. "Chile plays more offensively, while Spain has excellent players and a very strong group. Switzerland is more European in style, relying more on set pieces and counterattacks."
Lucio said Brazil needs to focus on its own game regardless of which team it will face.
"In a World Cup, we can't pick opponents," the defender said. "We have to try to win our matches and face the next opponent the best we can."