Never mind that the clash will take place in the round of 16 of the Champions League and not the final, nor that this week's installment is only the first segment of a home-and-home contest that will be decided over 180 minutes, across two countries and won't anoint a victor until the beginning of next month.
Soccer needs a juicy storyline to spice up a season that has stagnated somewhat in both of its two most prominent domestic competitions, the English Premier League and Spain's La Liga, due to the utter dominance of United in the former and Madrid's failure to keep pace with its hated rival Barcelona in the latter.
Just as well then, that it doesn't get much tastier than Ronaldo, the second-best soccer player on the planet but the undisputed champion at dividing opinion, squaring off against the team that signed him as a teenager, nurtured him to greatness, then sold off him for a world record fee of $131 million.
Even in the United States the buzz has not gone unrecognized and Fox Soccer is expecting its largest ever audience for a Champions League broadcast other than the final – and will use the excitable Gus Johnson to call the game.
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Yet it is not just the media corps and fans searching for some mid-season drama who are drumming up the hype machine ahead of Wednesday's first leg at Madrid's Santiago Bernabeu Stadium; the importance of the outcome is mightily tangible for both clubs.
United began its season primarily seeking to avenge its heartbreaking surrender of the EPL crown to local rival Manchester City last season. Mega-spending City entered this campaign threatening to become England's dominant club once again, and so swift and defiant has been the United response that it has all but sewn up this season's title already, opening up a 12-point gap over City with just a third of the fixtures remaining.
Attention then, can switch to the Champions League with near totality, a tournament United has not won since 2008 when, you guessed it, Ronaldo capped off a spectacular season by helping the team lift the trophy.
United head coach Sir Alex Ferguson shows no sign of slowing down but it must be remembered he is now 71 and reality dictates that he has a finite number of opportunities left to seize this coveted prize. With one of the strongest and most cohesive squads of his 26-year reign in Manchester, and the likely luxury of being able to rest key players during EPL games later in the season, this may be his best chance.
First though, Ronaldo stands in the way with a point of his own to prove.
The Portuguese forward looked ready to become the player of his generation at the time he left United in that blockbuster transfer and has maintained an almost absurdly high standard with 182 goals in 179 games for Madrid.
Yet he has still been overshadowed in Spain by Barcelona's Lionel Messi, who recently added his fourth consecutive world player of the year award and is already hailed as one of soccer's historical greats at the age of 25. Nothing short of a Champions League title would be enough to give Ronaldo a chance at wresting that individual crown from Messi, and even then perhaps not.
For all the importance and the anticipation, there is nothing but friendly platitudes bouncing back and forwards this week, with Ferguson insisting that Ronaldo's improvement since he left United has been such that it would now cost "hundreds of millions" to buy him back.
Ronaldo, who by many of his off-field antics has earned a reputation as a not particularly pleasant individual, nevertheless had words of surprising warmth for Ferguson and his former employers.
"It was a fantastic part of my life there," he told British reporters last weekend. "Maybe it was the time I enjoyed my football the most. It was a dream.
"I arrived at United aged just 18 and [Ferguson] taught me how to grow up properly in the football world. He was like a father to me."
But he will be acutely aware of the pressure upon his shoulders this week as Madrid tries to resurrect something from an otherwise doomed campaign, with Barcelona 16 points ahead in La Liga and the future of Madrid head coach José Mourinho very much in limbo.
Ronaldo's ability to step up when it matters most has often been called into question and he has become regularly agitated at aspersions cast on his mental mettle. Wednesday, and the return leg in Manchester 20 days later, offers the perfect opportunity to quiet those doubting voices in a contest that shapes up as the best 2013 has to offer.
Martin Rogers is a soccer columnist for Yahoo! Sports