Frenchman Le Guen did not allow an icy Bloemfontein evening to cool his confidence of a successful campaign despite a largely fruitless pre-tournament build-up and told a news conference Japan's miserable form mattered even less.
"I see the friendly games as not very important," Le Guen told reporters at the Free State Stadium in reference to Japan's dire run of four defeats and a draw in their last five games.
"I watched all of their games and they did well sometimes, for example against England. I know it will be a tough game," he added.
Stalwart defenders Rigobert Song and Geremi have begun to take a backseat in the Indomitable Lions side with the emergence of talented youngsters like Nicolas Nkoulou and Alexandre Song, but striker Samuel Eto'o remains their most gifted player.
The three-times African Player of the Year has more than 40 goals for his country and could expect to add to his tally if Japan fail to tame Cameroon's physical presence on Monday.
"Eto'o is our captain, he is an important player, he is the iconic figure in Cameroon. He knows what works for him as well as the Cameroon team," Le Guen said.
"He is a champion and knows how to concentrate on the things that matter."
The former Rangers and Olympique Lyon coach conceded the Netherlands are likely to top Group E with Cameroon and Denmark likely to fight it out for second, providing Japan do not spring an unlikely surprise.
Whatever their route, Le Guen is aware what his adopted country expects.
"I feel happiness to lead the team of Cameroon. I feel the huge expectation of the country and we have certainly done everything to make sure the preparation is well underway. I think we are ready to showcase our talents," he said.
"The aim is to go as far as possible and perhaps equal the glorious 90s," he added in reference to Roger Milla and his team-mates who fired Cameroon to the 1990 World Cup quarter-finals.
