Portugal coach Fernando Santos admitted on Friday that Cristiano Ronaldo had been unhappy to be dropped to the bench as he pleaded for a line to be drawn under the affair.

The veteran striker was a substitute for the first time at a World Cup since 2006 for his side's last-16 match against Switzerland, which they won 6-1.

A report in Portuguese newspaper Record said Ronaldo had threatened to quit the squad after he was told he was not in the starting line-up.

The Portuguese football federation denied the report and Ronaldo himself took to social media to state that the squad was "too united to be broken by outside forces".

Santos, speaking on the eve of Portugal's quarter-final against Morocco, said he had spoken to Ronaldo on the day of the game against Switzerland.

"I invited him to my office, and told him 'you will not be one of the starters', so it would not be a surprise," he said.

"I told him he would be important (but) in terms of the strategy, I told him 'it's better for you not to play'. I saved him for the second half."

Santos said five-time Ballon d'Or winner Ronaldo never threatened to leave the team camp, although he was upset about being dropped.

"Cristiano, for obvious reasons, was not very happy about it," said Santos. "He's always been a starting player except for one or two games on the bench -- obviously he was not happy.

"He told me 'do you really think it's a good idea?' But we had a normal conversation in which I explained my viewpoints.

"Of course, he accepted. We had a frank and normal conversation, he has never told me he wanted to leave our national team."

Santos said Ronaldo showed his commitment to the team by celebrating Portugal's goals and leading the players to applaud the fans.

"It's high time we stop with this conversation, stop the controversies," said the coach, trying to draw a line under the affair.

"It's high time for you to leave Ronaldo alone, in acknowledgement for what he's done for Portuguese football."

Santos hinted that he might bring the 37-year-old back into the team to face Morocco on Saturday, saying the north African side would provide a different challenge from Switzerland.

"They are an extremely well-organised team with high quality and potential, and many players at Chelsea, PSG, Bayern," he said.