Cameroon coach Volker Finke apologised for his team's performance in a 4-0 defeat to Croatia on Wednesday.
The Indomitable Lions were already behind 1-0 when Alex Song was sent off for striking Mario Madzukic in the back just before halftime. The disadvantage was too much and Croatia put the game out of reach with three second-half goals.
Finke said he was disappointed with how his team responded after being reduced to 10 men.
"It wasn't enough for me as coach," Finke said. "Everybody has to do something more when it's 10 versus 11. After today, we must be clear to prepare for our last game against Brazil.
"Sorry for this result. The style of defending and poor behavior from the red card is why we gave up four goals."
With no points from two matches, Cameroon are now unable to advance from Group A, meaning their finale against Brazil will be for pride only. Finke sees it as an opportunity to erase the bad images from Wednesday's defeat, which included a brief altercation between teammates Benoit Assou-Ekotto and Benjamin Moukandjo.
"It's very important to present a good team and a good match," Finke said. "I want to present another face of this team. We have to play 11 versus 11. We have to prepare this game very seriously and all players are disappointed now."
As for the clash between Assou-Ekotto and Moukandjo, Finke would only say, "The atmosphere is unhealthy."
Midfielder Eyong Enoh also said it was important for Cameroon to put on a good showing against the hosts in their final game.
"It would be good for us to finish on a good note. It will be difficult," Enoh said. "I am disappointed. I know the team is much more disappointed than me. This is the right time for all the fans to be behind the team so we can push to be in a better position.
"We started the game on a high note. We wanted to put them under pressure. When we came back in the second half after the red card it was difficult.
"I don't think this match is a formality. Hopefully we can get something from the game against Brazil to bring back home."
Finke said the fitness of star striker Samuel Eto'o is improving with each day, and hoped to have him against Brazil. But with Cameroon's World Cup dreams over for another four years, Finke also looked to the future.
"We have to look forward because there are some players for the future in this team," he said. "This is why we have to go straight and look in the right direction."