Queiroz's team, who have three points in Group B, can still progress to the last 16 of the tournament ahead of their meeting with Ronaldo's Portugal on Monday evening.
The Iranian coach, who was Sir Alex Ferguson's assistant while Ronaldo was at Manchester United, said that the Real Madrid attacker "makes the difference" for the national team.
"Portugal has the magic formula to win the World Cup, which is to have great team but also a player like Ronaldo that makes the difference," Queiroz is quoted as saying by The Mirror.
"There is always a Maradona, a Bobby Charlton, a player in a great team who makes a difference. For Portugal that is Ronaldo.
"Portugal are so powerful and for me they are one of the favourites to win the World Cup. So to be here knowing we are still alive and fighting for our dreams and a historic qualification for second round with a team like Portugal makes me happy and the players very proud."
Ronaldo has scored four goals so far at the World Cup.