Queiroz admitted his side refrained from going forward to avoid falling into a trap laid by the counter-attacking Elephants but said Portugal could not afford to hold back in their remaining games in the World Cup's toughest group.
"This result didn't embarrass us. This is the hardest group and only two candidates will move forward," he said of Group G, which includes five-times champions Brazil, who eked-out a 2-1 win over a stubborn and determined North Korean team on Tuesday.
"There was concern, there was nervousness, we normally attack more. We didn't do that, we were cautious and balanced to prevent them from counter-attacking."
Portugal travel to Cape Town on Monday to face North Korea, a defensively solid unit that excels in attacking breaks, whom Queiroz appeared to write off - a dangerous move given the reclusive state's apparent determination to gain the respect of the outside world through its soccer.
"It's important we play intelligently. It's now time for Portugal to play a team (North Korea) that's not a candidate to move forward and our final game (against Brazil) is no time to defend," he said.
"Like all the teams, we must now put all our cards on the table. The players were nervous and anxious and that makes it more difficult. Our offence will be completely different in the next matches."
But even with a tactical shift, firepower may be a problem for Portugal, especially given their reliance the world's most expensive player, Cristiano Ronaldo, who failed to score in qualifying, despite his staggering displays for Real Madrid.
But Queiroz said Portugal had more in the tank and did not care about pretty play in what is being dubbed the "Group of Death", nor whether they cruised or scraped into the next round. "Everyone knows only two can advance, no matter how much quality football you can play," he said.
"Whether we are first or second, I don't care, I just want to move forward and get out of here."
