Iran have only played two matches since the 2014 World Cup, a 1-0 victory over South Korea in November and a 1-0 win last Sunday over Iraq in Sydney.
The Iranians kick off their Group C Asian Cup campaign against Bahrain in Melbourne on Sunday and thereafter face United Arab Emirates and Qatar.
In a chat with reporters, Queiroz made no excuses just saying they were there to play football.
"No excuses, no explanations, no sorry, we are just here to play the game," Queiroz said.
"And with the team spirit that we've been showing in the other games, we have a good chance."
When questioned whether he thought that his side were a much improved outfit since their World Cup participation, Queiroz said "no." Iran was eliminated from the group stage in Brazil.
"It's worse now because we did not have the preparation we should have," Queiroz said.
"When you gamble too much with a bad preparation your chances are not so high as before. Our expectation was to come here with more camps and more games," he added.
In its other group games, Iran plays Qatar on January 15 in Sydney and then the United Arab Emirates on January 19 in Brisbane.