The three-time champions head into the tournament as one of the favourites despite having played just two friendlies since the 2014 World Cup.
Queiroz's side overcame Iraq 1-0 in Sydney on Sunday, with the win coming three months after they beat South Korea by the same scoreline in Tehran.
Despite saying Iran was looking forward to the clash with the Bahrainis, Queiroz was quick to stress his side's preparations for Asia's biggest tournament have been far from ideal.
"We are looking forward to playing this game against Bahrain, but now it is time to rest and train and prepare ourselves mentally," said the former Real Madrid coach.
"We have not improved since the World Cup. It is worse now because we have not had the preparation we should have.
"When you gamble too much with bad preparation, your chances are not as high as before."
Iran are Asia's highest-placed nation, ranked 51 in the world, and are making a record-equalling 13th appearance in the tournament after securing their place with an unbeaten qualifying campaign.
Despite rumours of an exit following the World Cup, Queiroz decided to remain as coach and is now keen to continue to give his all for the nation.
"I feel totally committed and loyal to the players and their wishes and desires to do well at this Asian Cup," he said.
