Cristiano Ronaldo's spat with South Korea's Cho Gue-sung frustrated Fernando Santos, who was unsure on reports surrounding the Portugal captain's future.

Ronaldo was involved in an exchange with Cho during his side's World Cup defeat to South Korea on Friday, where he appeared to get into a verbal tussle with his opponent as he was substituted.

The 37-year-old confirmed after the game that his frustrations had been with Cho, and not at Santos' decision to take him off.

While Santos has put the matter behind him ahead of Portugal's last-16 tie with Switzerland on Tuesday, he made it clear he was not impressed by Ronaldo's reaction.

"Did I see the images? I did," he said, in reference to footage of the incident. "Did I like it? Not at all. I really didn't like it at all.

"But from then on, these matters are resolved internally. From there, we think about the next game, for which everyone will be focused. The matter is over."

News emerged shortly before Santos' pre-match press conference that Saudi Arabian side Al Nassr were close to signing Ronaldo, who is a free agent after leaving Manchester United.

"I haven't spoken to him about this. I didn't know about this," Santos said.

"Someone only told me a few minutes ago. But that's his decision, and something that he has to deal with. We are focused on the World Cup and this team."

Ronaldo has scored only once in Qatar, converting a penalty he won in Portugal's 3-2 win over Ghana in their opening Group H match.

He became the first man to score at five different World Cups in the process, though he is yet to score in a knockout game in the competition.

Indeed, only Brazil great Roberto Carlos has had more attempts (29) without scoring in the knockout stages than Ronaldo (25) since 1966.