The 62-year coach has revealed that although his team are still not favourites to qualify for the quarter-finals, they will stick to their guns against the Seleccao
The 62-year-old also revealed that his players are in a confident mood ahead of the match against the Seleccao on Wednesday.
"[We will play] against Portugal exactly the same way that we did against Netherlands,” he said during a press conference on Tuesday.
"These are two countries that really know each other, as we met in qualification for the World Cup and the Euros. We have been the lucky ones. It took luck to get where we are today. It's not just form, it's also a little luck," the coach pointed out.
"There are many things that can influence a game, but as it looks now, as we say in Danish, both choose from full shelves.
"We come with a good feeling from the first game, that's not a lie. Victory begets confidence," Olsen stressed.
Olsen then reiterated that Denmark are still the underdogs in the group, but that the win over the Dutch helps them a great deal.
"We are not favourites against Portugal, we weren't against the Netherlands and we won't be against Germany.
"When we play Norway we are favourites, but not against these teams," he pointed out.
"Of course if you don't take points from the first game, you don't have the same confidence. But I saw the match against Germany. The Portuguese played well and deserved a point surely. They had a bad result but they played a good game."
The Danish coach then stated that his side will not sit back and defend against Cristiano Ronaldo and Co.
"We are not trying to play only for one point, we always try to win. But if afterwards we only get one point that's ok. But we always play to win," he pointed out.
Olsen shares the view that the group could be decided on Wednesday, with victories by Denmark and Germany practically ensuring their safe passage into the quarter-finals.
"The future is tomorrow and tomorrow we have to do well," Olsen stated.
"Anything is possible. It's the same every time. I think Portugal are a very sharp team," he said.
"It's a big step, we have two more games to go, but that's what we're going for," he concluded.