The Portuguese have one point from two games in Group G and need a win against Ghana in their final game to have any chance of progressing to the knockout stages.
However, the Real Madrid superstar has stated that his team are unlikely to appear at the business end of the Brazil tournament.
The Daily Mail quotes Ronaldo as saying: "Maybe we are an average team. It would be a lie to say that we are a top team. We have a very limited team and we are not at the best level.
"This does not enable you to beat top teams. There are no miracles. We knew we would have a tough group, with perhaps teams better than us.
"I am not a hypocrite — I never thought we could be world champions, we have to be humble and know our level."
Paul Bento's side drew 2-2 with USA on Sunday.