OK, he's broken a tournament record by becoming the first player to score a goal at five World Cups, but since converting that penalty in Portugal's opening game, Cristiano Ronaldo has had a rather quiet time of it.

Maybe he's about to burst into life in the knockout stage — and erase a blemish in his glittering career: None of Cristiano Ronaldo's eight World Cup goals have come in the knockout stage.

The five-time world player of the year heads into the round of 16 in likely his final World Cup facing Switzerland, which hasn't advanced beyond this stage since 1954.

Don't be fooled, though: This is the same Switzerland that eliminated France in the last 16 at the European Championship last year and has become one of its continent's most consistent teams.

Portugal might need Cristiano Ronaldo to start delivering. And the player himself will surely want to put himself back in the spotlight, having seen Lionel Messi — his great rival — perform so well for Argentina in its win over Australia in the last 16 and Kylian Mbappé — the man who is fast establishing himself as the sport's new superstar — already rack up five goals for France on its path to the quarterfinals.

Still oozing self-confidence at the age of 37, Ronaldo continues to back himself to perform at the highest level, yet his last two performances in the group stage were underwhelming. His only goal so far has come from the penalty spot in Portugal's opening victory over Ghana.

Portugal won its first two group games to advance and little should be read into the loss to South Korea, given coach Fernando Santos rotated heavily — even if Ronaldo started for the third straight game.

He'll be playing for the fourth time in 13 days and that's quite the workload these days for Cristiano Ronaldo, whose game time has been managed for the past year and a half at Manchester United.

The other Ronaldo subplot is that he is still trying to convince potential suitors he is worth investing in when the World Cup is over, now he is a free agent after leaving United in contentious circumstances.

Scoring goals in the World Cup knockout stage would go a long way to securing himself one last big move.

Portugal will welcome back its leading players rested against South Korea, like Bruno Fernandes, Bernardo Silva and Ruben Dias. Joao Felix should also return up front to play alongside Cristiano Ronaldo, whose tally of international goals stands at 118.

Santos must decide whether to play Raphael Guerreiro at left back, and return Joao Cancelo to right back, or leave Cancelo in that position to accommodate Diogo Dalot at right back.

Portugal hasn't got past the last 16 since making the semifinals in 2006 — and that was the only time Ronaldo has advanced beyond the quarterfinals.?

As for Switzerland, the danger man is Breel Embolo, who scored twice in the group stage and four times in his last five games for his country.

It is one of two all-European matchups in the last 16 and the winner will play either Spain or Morocco in the quarterfinals.