The 38-year-old brought up a double century during June's showdown with Iceland and marked that milestone with the only goal of the game - his 123rd in national team colours.
With six goals and four assists to show from four games in the Saudi Pro League so far this season, Ronaldo's spot at the tip of the attack is surely under no threat, while Bernardo Silva and Rafael Leao seem set to join him in the final third.
Both Nuno Mendes and Raphael Guerreiro are out due to injury, so Diogo Dalot could take up a left-wing back position, having impressed on that side during Manchester United's recent loss to Arsenal.
Barcelona new boy Joao Cancelo will likely fend off competition from Nelson Semedo to continue on the right-hand side, while Bruno Fernandes will pull the strings in the engine room as ever.
Ruben Neves was given the nod against Iceland three months ago, but Joao Palhinha certainly has a strong case to displace the Al-Hilal man in Bratislava, while Manchester City's Matheus Nunes is not involved.
Vice-captain Pepe is also absent from the squad this time around, so a man 21 years his junior in Antonio Silva could link arms with Ruben Dias and Danilo Pereira in front of Diogo Costa, although Goncalo Inacio and the uncapped Toti Gomes are alternative options.
Portugal possible starting lineup: Costa; Pereira, Dias, A. Silva; Cancelo, Palhinha, Fernandes, Dalot; B. Silva, Ronaldo, Leao
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