The two-time European Cup-winning coach has labelled the Portugal international as better than Diego Maradona and Pele, and believes Sir Alex Ferguson will have a hard time keeping the explosive attacker quiet upon his return to Old Trafford.
The former Inter and Chelsea coach did insist however that it would be down to a complete team performance if his side are to secure their place in the quarter-finals of the competition.
Asked what one quality would make the difference against United, Mourinho told ITV Sport: "To be my team, nothing else. If we are my team, we will win.
"How do United stop Cristiano Ronaldo? That’s not my problem. It's never a problem – I never want to stop Ronaldo. It's their problem.
"He is the best. The best in the world, yes. Probably the best ever.
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"We never say Cristiano is responsible when we lose a match and we can't think he is the only one who wins it. Without the team he is nothing but the team without him is not the same."
The enigmatic manager claimed on Monday that the "world would stop" to watch the two European giants go head-to-head, however, he insisted all eyes would be on the match and not on him.
The 50-year-old also admitted that his next job would probably be in England, although he was quick to dismiss reports that he was looking to leave los Blancos at the end of the season and asserted that his full attention was on helping Madrid progress in the competition.
"Yes, England is probably my next job," he added. "But when, I have no idea. It might not be this summer. I don’t know.
"I don’t think about my future. My future is not important, especially before a match of this dimension. I want to do everything to help Real win it. I want to enjoy every minute of this match."