Their careers have followed the same arc, and they have often met in the biggest games. So excuse the dejà vu when Sir Alex Ferguson's Manchester United travels to Jose Mourinho's Real Madrid for the first leg of their Round of 16 UEFA Champions League matchup this Wednesday (live on FOX Soccer , 2PM ET). Yet this game may well be different: the Scottish general has a chance to deal the Portuguese taskmaster a major blow, the likes of which Mourinho has yet to experience as a manager. For, if United is able to eject Real Madrid at this stage, Mourinho is unlikely to get another chance with the Spanish giants.

Mourinho's career has been so accomplished that only Ferguson's can exceed it. In fact, the charismatic Mourinho made his international breakthrough against Ferguson's United when his FC Porto side upset them in the Round of 16 of the 2003-04 UEFA Champions League. Porto came from behind to win 2-1 at home. Two weeks later, United seemed to have the necessary score line to advance on away goals when Paul Scholes put them ahead in the 32nd minute. But in the 90th minute, Costinha scored an equalizer, knocking United out. Mourinho celebrated exuberantly and then rushed off the field and into the players' tunnel without acknowledging anybody after the final whistle, the first of the many curious acts we've come to expect from him.

Porto won the entire tournament that year, bookending Mourinho's meteoric rise and marking his arrival at the very top. His astonishing ascent had begun when he became Sir Bobby Robson's interpreter at Sporting Lisbon in 1992, having reached no higher than jobs as a scout or assistant coach with minor Portuguese clubs previously. Later, he followed Robson to FC Porto, and then to Barcelona.

Louis van Gaal inherited the wildly ambitious translator at Barca in 1997. But as Gerard van der Lem, van Gaal's assistant at the time, recalled to Dutch magazine Voetbal International recently, "Louis wasn't sure what to do with Mourinho." Mourinho was multilingual, well-educated and worldly. But, said van der Lem, "He didn't know anything about football. He didn't know how to build up a training session. We couldn't leave that to him. He paid close attention though. Everything we did he scribbled down furiously. He kept a diary. He soaked up all that information."

Van Gaal, fastidious and studious himself, nurtured Mourinho, first letting him manage Barcelona B and then the first team in the unheralded Copa Catalunya.

After serving out his apprenticeship, Mourinho briefly managed Benfica - he quit after just nine league games when the new chairman wouldn't extend his contract -then overachieved with Uniao de Leiria before winning both the UEFA Cup and Champions League with Porto. At Chelsea - where Mourinho announced that he was "a special one" upon his appointment - he crossed paths with Ferguson regularly. He won the Premier League in his first two seasons there, while Ferguson won it in his final full season. They honored the other's teams by having their squads form an honor guard - lining the players' tunnel and applauding the other team when they emerged from it - when they won championships. They became friends. And Mourinho, who at 50 is 21 years Ferguson's junior, is considered his heir apparent.

To this day, Mourinho doesn't shy away from admitting his admiration for and envy of Ferguson. "Sir Alex is Man United; Man United is Sir Alex," he told FOX Soccer on Sunday. "I would like to have the same kind of experience he had all his life. Which is to be in a club and you know that you are working for this club for many, many years."

In 2008/09, Ferguson got his revenge and knocked Mourinho, then with Inter Milan, out of the Champions League in the Round of 16. Mourinho won the whole thing again the next season, and summarily moved on to Real. And here's where things get sticky.

Real is already out of the Spanish league title race, having stumbled far too often early in the season, allowing a surging Barca to build out an insurmountable 16-point lead. If United keeps Real from winning Europe's most coveted trophy for an 11th consecutive year, all that will remain for Mourinho to win is the Copa del Rey, Spain's domestic cup competition. And that won't save him.

Winning only that consolation prize was tolerated in his first season with the Spanish juggernauts, but won't be in his third. A mutiny already threatens his locker room, and several club stalwarts have apparently suspended their confidence in their manager. Clubs have only had limited tolerance with Mourinho's controlling ways, boundless ego and grating outspokenness. So if Mourinho doesn't win anything for the first time since the 2001-02 season - excepting the 2007-08 season, when he left Chelsea a month into the season and didn't work until the next summer - his end at Real will surely be nigh.

Even Mourinho acknowledges that Real won't be the club where he gets the long tenure he covets. "I am the coach of Real Madrid but I was the coach of Inter, I was the coach of Chelsea, I was the coach of Porto," he said. "And I will be the coach of another team."

The pressure in this contest is squarely on Mourinho, as Ferguson has all but clinched the English Premier League with over three months to play. After defending league champions Manchester City's unsightly 3-1 loss to newly-promoted Southampton on Saturday and United's unfettered 2-0 win over Everton the next day, the Red Devils are 12 points loose at the top, giving them the luxury of saving resources for the continental competition.

Rather than acknowledge the mounting heaviness on his shoulders, however, Mourinho's reacted with the hubris that is habitual to him. "The match is only on Wednesday but I would like the match to be tonight," he said. "Around the world people in love with the game will stop to watch this match."

They will. And if United puts the contest away early, they might witness the first real failure in Mourinho's laureled career.