Real Madrid captain Sergio Ramos has denied deliberately picking up a yellow card in Wednesday's Champions League match against Ajax in order to serve a suspension before the quarter-finals.

Ramos was booked in the 89th minute of Madrid's victory in Amsterdam, just minutes after Marco Asensio's late goal saw Madrid complete a comeback from 1-0 down, and he will now miss the second leg at the Bernabeu.

Speaking immediately after the match, Ramos was quoted as saying he "would be lying" if he denied deliberately earning the booking, comments which could attract an extended ban from UEFA, who confirmed on Thursday that they were investigating.

But the defender then used social media to deny it was deliberate, and on Friday he gave an interview to Spanish newspaper Marca to again deny any wrongdoing and claim his post-match comments referred to deliberately giving away a free-kick to prevent an Ajax equaliser.

"I'm very surprised about all this," Ramos said. "I was referring to forcing the foul, a foul that was inevitable. Not to forcing the booking."

Asked if he knew the foul was likely to lead to a yellow card and a ban, he added: "Yes, but I had no choice.

"It was a very dangerous counterattack in the 88th minute, with an open match and the tie as well.

"That's why I said that I would lie if I said I did not know that I was carrying a penalty, just as I knew that I had no other choice than to make a mistake. And that's what I meant when I said that in football you have to make complicated decisions.

"If I had wanted to force a penalty, I could have done it in the group stage, in the match against Roma because we were already classified as first of groups and the last game, against CSKA, was inconsequential. By the way, a match in which I did not play."