There is a temptation to think that whoever triumphs in the game that will captivate Europe next week will ultimately be fodder for Jose Mourinho.
Despite the flair and young talent in Jorgen Klopp's Borussia Dortmund side, they showed signs of hesitancy and callowness in the two legs against Malaga. Real Madrid and Mourinho will expect to punish those failings and they will be confident of making the Champions League final. Dortmund are entitled to point to the spirit they showed in scoring twice in injury-time to turn the tie around last week, as well as all they have achieved under Klopp, and their unbeaten record in this season's competition.
Most importantly, Klopp will point to Dortmund's record in the group stage against Real Madrid when they beat Mourinho's side in the Westfalenstadion in the home tie and were a minute away from victory at the Bernabeu.
If Dortmund feel that they will be dismissed as potential finalists, then they can also recall the mood before they played in Madrid last November. Mesut Ozil explained that his side had started the season badly but things were improving and, while they wouldn't be underestimating Dortmund, the game was theirs to win. "If we put into practice what the coach has told us, we will certainly win the three points." Instead Ozil scored in the 90th minute to claim a point for Madrid.
Dortmund might hope for complacency and they could also claim to be a more cohesive unit than Madrid. Many within the Madrid squad are apparently longing for Mourinho's departure while hoping that his remarkable ability to win the Champions League can sustain them this time.
Madrid may have been fortunate in Nani's sending-off at Old Trafford and in their quarter-final draw but in Manchester Mourinho didn't allow his side to miss their opportunity. He sent Luka Modric on to unpick the ten men while whispering Iago-like to Alex Ferguson about the injustice of it all.
Despite all of Dortmund's qualities, the draw gives Mourinho the best opportunity of sustaining his legend and again leaving behind the European Cup as he departs. If Madrid can forget about their civil war and claim a tenth European Cup, he will be able to insist that the future doesn't belong to someone else. Even if, as seems likely, he has returned to his past and to Chelsea in order to move forward.
The alternative universe will be making its case in Munich and Barcelona, with Pep Guardiola the figure both sides will want to impress. Guardiola will return from sabbatical next season to a club and a country that believes, with good cause, that it can dominate European football. Munich have lost two of the past three finals but the semi-final will demonstrate if the scars from last season's remarkable defeat to Chelsea are permanent.
Certainly, in Germany they are anxious that the failure in their home stadium, Germany's defeat to Italy in the European Championships and then its inability to hold a four-goal lead against Sweden in the World Cup qualifiers reveals a diminishing in the character of their footballers.
Bayern's form this season and the manner in which they crushed Juventus would appear to be a rebuttal of these arguments and an easing of the fears. Bayern have regained the Bundesliga and will now aim for their first European Cup since the side of Stefan Effenberg and Oliver Kahn led them to a penalty shoot-out victory in 2001.
The first leg of Bayern Munich and Barcelona will take place three weeks after Messi picked up his hamstring injury against PSG. For a normal player, this time frame would make him anxious but Messi,
as he demonstrated last week, is not a normal player. He may have been only half-fit last week but his contribution was decisive and his introduction altered the game.
He is essential to the functioning of the side, even while men like Xavi and Iniesta control midfield.
There are those like Alex Ferguson who wonder why Guardiola walked away and point out that the pressure will never lessen at the highest level. There may be some within the Barcelona set-up who are asking the same thing.
They have been touched with tragic misfortune this season in the illness of Tito Vilanova. Against Milan, they demonstrated in the most convincing fashion all they are capable of but despite that performance and their dominance in the league, Jupp Heynckes will believe that Bayern can unsettle a team that can be unsettled.
If Munich triumph and go on to win the competition, Guardiola may discover the true meaning of Ferguson's words. Even if they fail, there will be an expectation now that they are in a position to dominate Europe.
Barcelona will believe, despite all the chaos, that their dominance has not ended. Barcelona know what it feels like to be loved and to win. Jose Mourinho knows how to win and he knows how to upset everybody's plans.