Bento: Ronaldo was not rushed back into action
The Real Madrid forward was seen wearing ice packs on his knee in preparation for the finals having struggled with the problem towards the end of last season.
Ronaldo was unable to keep Portugal in the competition despite playing every minute of every group game in Brazil, and he left with just one goal to his name.
Questions were raised as to the fitness of the talismanic captain, but Bento insists the 29-year-old was fit to play.
"When he reached the World Cup he was not 100 per cent," Bento told Portuguese TV station TVI. "But then he was able to train and play.
"He played with effort and sacrifice and was medically fit, he would not have played had he not been.
"There was not any pressure to speed up his recovery."
Portugal were eliminated from the World Cup on goal difference, their 4-0 defeat to Germany in the opening game ultimately proving their undoing as the United States progressed.