The subtext to this draw is Sir Alex Ferguson's and José Mourinho's attempt to capture a third Champions League title
A delicious shudder of excitement and anticipation ran through two of Europe's great football cities on Thursday morning when the draw for the Champions League's round of 16 produced a meeting between Manchester United and Real Madrid, alongside several other extremely promising ties.
Arsenal versus Bayern Munich, last year's beaten finalists, and Celtic versus Juventus, the current Italian champions and league leaders, are contests to stir the blood. So are the scheduled encounters between Milan and Barcelona, members of Europe's old football aristocracy, and Shakhtar Donetsk and Borussia Dortmund, two of the most interesting teams to emerge from the group stage, who played important parts in the early elimination of Chelsea and Manchester City.
But it was to the match between United and Madrid that Paddy Crerand was referring when he unleashed a tweet within seconds of the announcement: "A clash of the titans, two biggest and most romantic clubs on the planet." Crerand, of course, views the world from a United perspective, having played a part in the club's first European Cup success 45 years ago. As a Glaswegian of a certain age, he also remembers the night in 1960 when the Madrid team of Puskas and Di Stefáno drew 135,000 to Hampden Park for their 7-3 victory over Eintracht Frankfurt in one of the greatest club matches of all time.
United versus Real is a tie whose history goes back almost to the dawn of the competition – to a Madrid victory over Matt Busby's team in the 1957 semi-final, in fact, when Duncan Edwards, Dennis Viollet and Roger Byrne competed against Di Stefáno, Gento and Raymond Kopa – and whose appeal transcends loyalties: few neutrals could remain unmoved by the prospect of the matches to come, first at the Bernabéu on 13 February and then at Old Trafford on 5 March.
"It's the game everybody wanted to see and nobody wanted to see because everybody wanted to save it for later in the competition," John Alexander, United's club secretary, told Sky Sports. Certainly the tie will have the emotional weight of a final, given that it pits a side with a record nine wins in the competition against opponents looking for the fourth title that would lift them to joint fourth place in the all-time table, alongside Barcelona, Bayern Munich and Ajax.
On the pitch, Cristiano Ronaldo's return to his old club will be a focus of attention, with Robin van Persie keen to show himself capable of matching the goalscoring feats of United's former No7. The star of the 2008 European Cup-winning side, Ronaldo played his last game for the English club in the following year's final, which they lost to Barcelona, before his £80m move to Madrid.
Two men, however, will inevitably dominate the buildup. Both Sir Alex Ferguson and José Mourinho harbour a fierce ambition to capture a third title. The irresistible subtext is the belief that Mourinho is the man Ferguson would like to see succeeding him at United when the Scot eventually hears the cue to call it a day, which could come with a third victory in the European Cup. So were United to go on and win this season's competition, a stumble for Mourinho at this stage might put him closer to the manager's seat at Old Trafford.
It is nine years since the two faced one another for the first time, at the same stage of the 2003-04 competition, with an exultant Mourinho's unfancied Porto proceeding to the last eight at the expense of United. Since then they have met 14 times in head-to-head competition in European and English football, with the balance favouring the Portuguese over the Scot: six wins to Mourinho, three to Ferguson, and five draws. One of those Mourinho successes was his very first match in England, a 1-0 win for Chelsea on the opening day of the 2004-05 season.
"The fans will be very, very happy," Emilio Butragueño, the former Madrid striker and now the club's institutional relations manager, said. "It's going to be a thrilling experience for everybody."
For Mourinho, whose reigning Spanish champions now lie an apparently hopeless 13 points behind Barcelona in La Liga, it will also be a crucial one. Virtually certain to leave the Bernabéu at the end of this season, he will not want to do so without having the biggest club trophy of all to wave in the faces of his critics inside and outside the dressing room – not to mention potential future employers elsewhere.
The shaky performance of Premier League clubs in this season's European Cup is reflected in the bookmakers' latest prices against one of them winning the title: United are 12-1, with Arsenal at 33-1. The north London side, currently attempting to recover form and confidence after a sticky few weeks, will have their hands full against a Bavarian squad enhanced since defeat in their own stadium at the hands of Chelsea last May by the addition of the strong Spanish holding midfield player Javi Martínez and the prolific Croatian striker Mario Mandzukic.
Celtic, despite their ecstatically received victory over Barcelona in the group stage, are rated no better than 150-1 for the trophy as they approach the tie against Juventus. "In terms of glamour," Neil Lennon said, "it's a beauty. In terms of qualification, it's going to be very tough."
He could have been talking about virtually the entire round of 16, in which the contest between Milan, with seven titles, and Barcelona, with four, would normally sit at the top of the bill. Deprived of the sort of resources that once made the Lombardy club a natural destination for players of the calibre of Marco van Basten and Kaká, Massimiliano Allegri's team can no longer aspire to the old standards, while the Catalans are likely to be without their head coach, Tito Vilanova, who has just begun treatment for cancer of the saliva gland.
The ties between Galatasaray and Schalke, Porto and Málaga and Valencia and Paris Saint-Germain ensure that the final eight will include a handful of less glittering names, although Porto, twice winners, should never be underrated. At PSG, Europe's latest big spenders, Carlo Ancelotti will be expected by his Qatari paymasters to secure a dividend from their investment in the talents of Zlatan Ibrahimovic, Ezequiel Lavezzi, Thiago Silva and Javier Pastore.
In terms of stimulating football and close competition, however, it would be no surprise if the contest between the teams from Donetsk and Dortmund, featuring the likes of Willian, Fernandinho, Marco Reus and Mario Götze, turned into the star tie of a mouthwatering round.