You may disagree but it happened and it was one of the main reasons for the relationship problems between Queiroz and Ronaldo. In somes games he did play as the only striker and in others we started with Almeida or Liedson but his tactical changes in the second halfs would put him in that unconfortable position. Cmon you just have to remember Ronaldo´s reaction (the famous "Culpa da eliminação? Perguntem ao Queiroz) and some interviews where he showed that was unconfortable with his tactical positioning.
I don't remember all the intricacies, but the truth is there, Queiroz didn't always used him as a striker. And you can't blame him for trying Ronaldo at striker occasionally when there isn't any other half-decent option, there are actually decent options on the wings, and Ronaldo when playing in the wing wasn't working out as well. Ronaldo needs space, without it he's (relatively) limited. Queiroz is a shit manager at so many levels, but I take those Ronaldo's comments as a way to shove pressure of his own shoulders as well. And I don't blame him for it, in nowadays football a player can't single-handedly mask the weaknesses of a team no matter how good he is. Messi doesn't do it for Argentina either. You get the odd Forlanesque performance, but that's when it all works out well and it did that time. Far better players can't do that and even Forlán never repeated it. I hope Ronaldo does it for us, but I won't blame him if he fails to do it, nor I think he needs excuses for it if he can't.