Portugal boss Fernando Santos has insisted that Cristiano Ronaldo is not guaranteed to start every game for the national team at the 2022 World Cup.

No player has made more appearances (191) or scored more goals (177) for A Selecao than Ronaldo, who has hit the headlines this week due to his explosive interview with Piers Morgan on TalkTV.

The 37-year-old has found it difficult to show his best form for Manchester United this season, only scoring three times in 16 appearances in all competitions.

When asked about Ronaldo and the upcoming World Cup, Santos said that he was under no obligation to start the number seven, who would have to earn his spot in the side like every other player.

"Forced? This is not about forcing me. This is not a requirement. No one is forced to do anything here," Santos told reporters.

"The question could be, you could ask me, based on what Cristiano Ronaldo did [in recent weeks on the pitch] should he start? This is valid for Cristiano Ronaldo and all the players who are with the national team.

"If the head coach is forced to put a player in the XI... there aren't those things here."

Ronaldo was not involved in Portugal's pre-tournament friendly with Nigeria on Thursday due to illness.

Bruno Fernandes scored twice for the home side in Lisbon, while Goncalo Ramos and Joao Mario were also on the scoresheet in a 4-0 victory for the European nation.

Ronaldo is expected to be available for Portugal's World Cup opener against Ghana on November 24, though, and he will also be hoping to feature against Uruguay and South Korea in the group stage.

During his interview with Morgan, Ronaldo said that he was "very optimistic" of Portugal's chances, while also revealing that he would retire from international duty if his country won the trophy.

"I am very optimistic. We [Portugal] have a fantastic coach and we have a good generation of football players. I'm looking forward that we're going to it, an amazing World Cup," said the forward.

"[It's] going to be tough. Extremely difficult. But everything is possible. But of course we're going to compete."

Portugal have never won the World Cup, with their best-ever finish at the tournament coming back in 1966, when they came third.

"Yes. Retired. 100%," he said when questioned on his plans if he lifted the trophy.

Portugal were also fourth at the 2006 World Cup, but they have been eliminated in the first knockout round in two of their last three tournaments, including back in 2018. body check tags ::