Fernando Santos refused to guarantee the former Manchester United star would play the full 90 minutes at Lusail Iconic Stadium, having been unhappy with his reaction while being substituted in the eventful final group game against South Korea.
“I didn’t like it. Not at all. I did not like it. I really didn’t like it,” said Santos, who is facing calls to drop his key man.
On the prospect of Ronaldo starting against Switzerland, he added: “I only decide who is going to be in the team when I reach the stadium. I don’t know what the lineup is.
“That’s what I have always done and that’s what I am always going to do. It’s going to be the same here.”
He has made the huge decision to bench Ronaldo, with Goncalo Ramos coming in to lead the line instead.
Six points from Group H was enough for Portugal to book a last-16 tie against Switzerland, who held off a spirited Serbia side in their final Group G match, winning 3-2 to finish second behind Brazil.
Santos has reinstated his other first-choice players, including Manchester United playmaker Bruno Fernandes, who has scored two goals and laid on two assists in this World Cup so far.
Manchester City pair Bernardo Silva and Ruben Dias also return, while Santos’ other main dilemma was at left-back, with Nuno Mendes ruled out of the tournament. Joao Cancelo also misses out, so it’s Diogo Dalot on the right and Raphael Guerreiro on the left.
For Swiss boss Murat Yakin, Xherdan Shaqiri is now fit and firing after missing the Brazil defeat with a knock before scoring a fine goal on his return against Serbia.
Goalkeeper Yann Sommer and centre-back Nico Elvedi both missed the Serbia game due to illness - the goalkeeper returns but it is Fabian Schar alongside Manuel Akanji in defence.
Portugal XI: Costa, Dalot, Dias, Pepe, Guerreiro, William, Otavio, Fernandes, Silva, Felix, Ramos.
Switzerland XI: Sommer, Fernandes, Schar, Akanji, Rodriguez, Freuler, Xhaka, Shaqiri, Sow, Vargas, Embolo.