Sitting third in the group, level on 11 points with second-placed Israel and a point behind this week's visitors who have played two games fewer, Portugal cannot afford another below-par performance like last year's 1-0 defeat in Moscow.
With Ronaldo having been rested in his club Real Madrid's final two La Liga games, it would be easy for him to be putting his feet up but Portuguese Football Federation vice-president Humberto Coelho is confident the forward is focused on business.
"He always gives it all for the national team. Physically, it's not the best time of the year to play but other players had long seasons too," Coelho said.
"Russia are comfortably on top, with two games in hand and one point ahead, but we do not intend to drop the goal of reaching the precious second place, which gives us access to the playoff."
Group winners qualify for next year's World Cup finals in Brazil, while the eight best runners-up will play off over two legs for the remaining four places.
While the Portugal players are being urged to wait a few more days before enjoying some relaxation, some of Russia's were shown by Russian media last week to be smoking and drinking together on a night out.
Portuguese media picked up on it widely and when they asked striker Hugo Almeida what he made of the footage, he was pretty sympathetic.
"Sometimes it's important to unwind at the end of a long season, after so much effort and constant psychological pressure," he said.
Portugal coach Paulo Bento said that as well as end-of-season fatigue, another issue making preparations difficult was the fact his players were scattered around Europe with their clubs while most of the Russians play in their domestic league.
"We have players spread around many championships so it's more difficult for us to prepare," he said. "It's a handicap but not an excuse."
Only seven of Portugal's 25-man squad played for a club of their home nation this season.
Centre-back Pepe is suspended for the game at Estadio da Luz while Ronaldo, Nani and Fabio Coentrao, three of the country's key performers, are all racing to recover from small knocks.
Bento's side are especially keen to qualify for the World Cup as it is being held in fellow Portuguese-speaking Brazil and know that since they are behind Israel on goal difference with both having played six games, they must avoid any more slip-ups.
"We have to take [the] initiative and command the match for most of the time," Bento said. "We have no margin of error given the mistakes [we have already made]."
Russia coach Fabio Capello, who will be without injured forward Alexander Kokorin, hailed his team's good start to the qualifying campaign but said the job was far from done.
"We started well and left our rivals behind. But the qualifying tournament is a long way to go and we have no right to relax until we win our place in the World Cup finals," the Italian told the Rossiiskaya Gazeta newspaper.
"We have played just four ma
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