The pair crossed paths on numerous occasions during Ronaldo’s six-year spell in England, as Manchester United and Chelsea wrestled for Premier League supremacy.
Cole and Ronaldo also faced off while on international duty, although that rivalry was a bit more one-sided, with England being knocked out of two successive major tournaments by Portugal.
While Cole is now playing with the LA Galaxy in the MLS, Ronaldo is still playing world-class talent on a weekly basis but insists that he has never had it tougher than when he came up against the 35-year-old.
"Over the years I had some great battles with Ashley Cole, he does not give you a second to breathe," Ronaldo told Coach Mag.
"He was such a tenacious player when he was at his peak, quick, tough in the tackle. You knew it would never be an easy game."
Ronaldo was also questioned on the player he admired the most and, despite admitting the pair weren’t ‘good friends’, he insisted he had a lot of respect for Lionel Messi.
"There is a big mutual respect between myself and Lionel Messi," Ronaldo added. "The media like to make out like we have this big rivalry, but we don't.
"It is not like we are good friends, but there is a mutual respect on both sides."
He was also full of admiration for former manager Sir Alex Ferguson, who Ronaldo has repeatedly called a ‘father figure’ in his footballing career.
"I do see Sir Alex Ferguson as a father figure," Ronaldo added. "All my coaches have been important, but when I arrived at Real Madrid I was a man, when I arrived at Manchester United I was a boy.
"All of a sudden you are at one of the biggest clubs in the world, and at that time I needed somebody like Sir Alex."
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