Iran open their fifth World Cup campaign on Friday against Morocco in what Queiroz described as a "must-win" match in Saint Petersburg with the might of Spain and Portugal to come in Group B.
Queiroz's men romped through Asian qualifying without tasting defeat in 18 games.
But their preparations for Russia were disrupted as warm-up friendlies against Greece and then Kosovo were cancelled.
Earlier this week, Nike announced it had stopped supplying boots to the Iranian team due to US sanctions against the country.
"We are not ever using apologies or justifications, we are using the difficulties as a source of inspiration for our motivations to be strengthened during the games," said Queiroz.
The former Real Madrid coach swerved questions on whether the sensational sacking of Madrid-bound Julen Lopetegui as Spain boss two days before their opening game against Portugal raised his expectations of progress to the last 16.
For now, Iran remain the rank outsiders in the group but Queiroz is happy to play the role of underdogs.
"We admit that the favourites are Morocco, Spain and Portugal due to history, World Cup preparation, maturity and players in the best teams in Europe," he added.
"We concede that favouritism, but we don't tolerate that we are not capable to win. Nobody can undermine our expectations and hopes.
"We are here to compete with the favourites and we hope the gods of football speak higher and they make decisions."
Despite bowing out at the group stage four years ago, Iran returned home with pride, having held Nigeria 0-0 and come within seconds of also taking a point off Argentina until a last-minute moment of magic from Lionel Messi undid a defensive masterclass from Queiroz.
"No matter what happens on the pitch I want my players to leave the pitch with their head up," said Queiroz. "We leave the pitch bringing home pride, joy and happiness to our fans."