The Arab world's standard bearer, Morocco is in the quarterfinals on merit, too. The team has only conceded one goal - and that was an own-goal against Canada - and is proving so well-organized, with a sturdy back four headlined by Achraf Hakimi, a dedicated midfield anchorman in Sofyan Amrabat, two mercurial wingers in Hakim Ziyech and Sofiane Boufal, and a striker in Youssef En-Nesyri who occupies defenses with his relentless work rate.
Three key players might be struggling to be healthy enough to play against Portugal, though. Amrabat said he played with a back injury requiring painkilling injections in the match against Spain, during which captain Romain Saiss finished the game with his leg bandaged up after treatment and fellow center back Nayef Aguerd hobbled off in tears with an apparent thigh injury.
Portugal doesn't appear to have such problems, with Santos' squad depth so impressive that he could afford to leave players like Ronaldo, Joao Cancelo and Ruben Neves on the bench against Switzerland after they started every group game.
Santos said he picks his team according to the strengths and weaknesses of his opponent but it will be a surprise if he makes any changes after a match that thrust Portugal among the tournament favorites.
Even if he starts as a substitute again, Ronaldo - playing in his likely last World Cup - is expected to see some time on the field. Given the drama constantly surrounding him, he's sure to be a talking point whatever happens.