AL RAYYAN, Qatar -- Cristiano Ronaldo was "insulted" by South Korea player Cho Gue-sung as he left the pitch, according to Fernando Santos, as the Portugal coach sought to defend the striker's frustrated reaction to being substituted.
Ronaldo appeared to have a verbal exchange with Cho as he walked towards the benches and then put his finger to his mouth.
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The 37-year-old looked unhappy at the decision to bring him off in the 65th minute but after the 2-1 defeat which sent South Korea into the last 16, Santos insisted it was his interaction with Cho that had made the former Manchester United forward "angry".
"The player from Korea was insulting him telling him to go away, so that is the reason why he was angry, everyone saw that," said Santos.
"I saw the interaction with the Korea player and I don't have any doubts about it and if you see the images you see Pepe went towards the Korea player.
"He was not aggressive, he was only verbally aggressive, he was speaking in English to Cristiano, and Cristiano said, 'Perhaps he had a bad day.'"
Ronaldo told Portuguese reporters that Cho was trying to hurry him off the pitch.
"What happened was before my substitution, the South Korea player told me to get off quickly. I told him to shut up as he doesn't have that authority. There was no disagreement [with the coach]," Ronaldo was quoted as saying.
South Korean midfielder Hwang In-Beom had little to say on the incident.
"I didn't see it, I was too tired," he said. "I was looking at the ground, so I didn't see it and I have nothing to say."
Portugal still finished top of Group H despite conceding a 91st-minute winner to Hwang Hee-chan which saw South Korea edge out Uruguay for a place in the knockout rounds.
Santos' team are set to face the second-place team from Group H -- probably Switzerland, Serbia or Cameroon -- but he insisted defeat to South Korea should serve as a "warning" to his squad.
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"We are somewhat upset," Santos added.
"We are first in the group, but we wanted to win and have a better game to increase the morale of the players. But this result serves as a warning to our team."
Meanwhile, South Korea are set to face Brazil after qualifying for the second round for the first time since 2010.
They were heading out until Hwang's dramatic winner which saw them qualify on goals scored ahead of Uruguay, who exit the World Cup despite beating Ghana 2-0.
"Before the match Son Heung-min told me I was going to create something today," said Hwang.
"He said, 'We trust you.' When I went on as a substitute a lot of team mates also said they trusted me. When Son got the ball I was convinced he would pass to me and it was an excellent pass. It made my job easy.
"It was difficult waiting for the other result but we proved we could make it to knockout phase and we kept that trust. This is something we wanted and we expected. I want to share these great feelings with the Korean people back home."