Cristiano Ronaldo will not play in Portugal's World Cup warm-up game against Nigeria on Thursday because of illness, according to head coach Fernando Santos.

The Portugal boss also dismissed concerns about Ronaldo's interview with Piers Morgan in which he criticised his club, Manchester United.

Speaking at a press conference, Santos said: "Ronaldo has gastritis and did not train today in order to recover and rest.

"It's a condition that doesn't help much as it affects the players a lot, they lose a lot of liquid, they weaken. He won't be ready for tomorrow, for sure."

Santos continued: "[Ronaldo] didn't have to inform us about the interview. Isn't he free [to make his decisions]?

"What I'm interested in is what is being spoken about in our camp and not what is being said outside. We have to respect his decision.

"We have to respect the interview he gave. It has nothing to do with the national team."

Portugal begin their World Cup campaign against Ghana on November 24, before also taking on Uruguay and South Korea in Group H.