Qatar began their campaign with a 1-1 draw against Switzerland in California, while Canada also were held 1-1 by Bosnia and Herzegovina in their Group B opener in Toronto. Group B is finely balanced, with all four teams on one point.
Qatar, with a population of around 3.17 million, arrived at the tournament seeking to improve on their only previous World Cup appearance, when they hosted the 2022 edition and finished bottom of their group without a point.
"The word pressure is not in our mind," Lopetegui told reporters on Wednesday. "When you follow one dream, you're never under pressure. You are with a big ambition, big excitement, because we achieved one thing that never happened in the history of Qatar, which was to stay here.
"I think that it's (Qatar) one little country, but with a big passion, a big investment in the facilities, about how we have to improve every day," he added.
"Now we are not thinking about what we did against Switzerland, what was the past. Now we are only focused on being able to face one strong team."
With a squad drawn largely from their domestic league, Qatar have developed a cohesive team who have proved formidable in Asia.
They no longer carry the intense scrutiny that surrounded the 2022 tournament, though back-to-back Asian Cup titles and a favourable group have raised expectations.
"It was the first time with a lot of pressure," midfielder Abdulaziz Hatem said. "Maybe we didn't have the experience, but now we are here. We have the experience. We are ready.
"We will see tomorrow what will happen. But I hope we play a good game and continue making history. It's difficult, not easy for sure, but I think we are able to do it," he added.