Ronaldo’s omission would be a surprise following man-of-the-match performances in the 2-2 draw with Mexico and the 1-0 victory over Russia, when he scored the winner.
However, Fernando Santos, who led Portugal to their first piece of international silverware at Euro 2016 in France, says he wants to maintain the fitness levels in his squad.
“We have to manage the players and there will be rotation based on how the players are feeling. It is easy to do when you have a group you trust,” he said. “New Zealand gave Mexico a few problems and we will have to be on our toes,” he added.
Going into Saturday’s final round of games in Group A, Mexico are top, level with Portugal on four points but ahead because they have scored one more goal.
The South Americans face Russia, who are a point behind in third. New Zealand are bottom and out of the competition after losing both of their games.
The Kiwis will breathe a slight sigh of relief if Ronaldo is rested, with the Real Madrid star netting 15 times in his last nine matches for club and country.
“Even if you take Ronaldo out of the team, you still have world-class players like Ricardo Quaresma and Nani,” said New Zealand coach Anthony Hudson. “We have a game plan and we won’t be overawed.”
Russia will advance if they beat Mexico in Kazan while a point would be enough for the Mexicans to progress.
After the draw with Portugal, Mexico coach Juan Carlos Osorio made eight changes against New Zealand, a plan that initially backfired before his side recovered after the break to win 2-1.
Star striker Javier Hernandez, left out against New Zealand, is expected to start while Osorio must replace the injured Carlos Salcedo and Hector Moreno in defence.
“We are extremely confident,” said Osorio. “For us it was very important to get three points against New Zealand and now against the hosts we feel that we have a great chance.”