Already through to the second round of the World Cup, Brazil wants to finish the group stage with a win over Portugal to keep its momentum going ahead of the round of 16.
The 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 on Friday in Durban. It leads the group with six points, two more than Portugal, a team that virtually clinched a second-round spot by 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 because of a red card 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 had until now 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 Stadium.
"It's important for the team to keep improving as the tournament goes on," Dunga said. "It's what we want to happen."
Brazil and Portugal are deeply connected nations. They are the only Portuguese-speaking nations at the World Cup, and Portugal enters the tournament with three Brazil-born players - Deco, Liedson and Pepe.
The teams 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 is set to avoid another high-profile match in the next round, against Spain. The group is wide open, however, with Chile, Spain and Switzerland with significant chances 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."
Brazil captain 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."
