Having opened their Confed Cup campaign with a 2-0 win over New Zealand, Russia face a step up against Euro 2016 winners Portugal and their troubled captain.
Spanish authorities accuse Ronaldo of evading 14.7 million euros ($16.5m) in tax and he has been summoned to appear in court next month in Madrid.
The four-time Ballon d’Or winner has protested his innocence and threatened to leave Real over the matter.
Club president Florentino Perez has said Champions League winners Real have so far received no offers for Ronaldo, the world’s highest-paid athlete according to Forbes magazine.
Despite the off-field disruption, Ronaldo picked up the man-of-the-match award in Portugal’s opening 2-2 draw with Mexico on Sunday.
The tax storm has followed him to Russia and Ronaldo’s future is the hot subject at each Portugal press conference, but Pepe says he is focused on the job.
“We’re professionals, we just think about doing our best and going as far as we can at this Confederations Cup,” said Pepe, who is out of contract at Real.
“This is the first time Portugal have been here, it’s a privilege to be here and Cristiano is just another player motivated to help Portugal as he always has done.”
Russia know one of the keys to derailing Portugal is ensuring Ronaldo has a quiet match at Moscow’s Spartak Stadium.
“The first place in group after the first game means nothing,” said Russian midfielder Alexey Miranchuk.
“It only matters after three games. We saw how dangerous Portuguese counter-attacks can be against Mexico. We must be ready for them.”
The hosts will have vocal home support as their captain and goalkeeper Igor Akinfeev is set to make his 100th international appearance.
Portugal coach Fernando Santos has said he will rotate his team during the tournament.
After Portugal’s defensive frailties were exposed against Mexico, Santos could inject some pace by starting with Gelson Martins, Nelson Semedo and Andre Silva.
Strangely, Portugal have never won in Moscow, losing all three of their previous games there, once to the former Soviet Union and twice to Russia.
Pepe says he expects a tough match, as Russia bid for a second group win to reach the semi-finals.
“The Russian team is very cohesive, they all work hard and shorten spaces, we’re preparing well and being humble,” said the 34-year-old.
“It’s going to be very difficult, but we have players who are very capable and are highly motivated.”
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