Sir Alex Ferguson says Manchester United v Barcelona would have made a glorious final - and he has a point.
Two of the greatest clubs in the planet though will have to make do with a tantalising semi-final clash made all the more mouthwatering by the chance to compare the supremely gifted Cristiano Ronaldo and Lionel Messi.
Right now they are arguably the best players in the world and over the next week, we should know who is top dog.
Last season at the same stage of the competition Ronaldo took on AC Milan's Kaka for that mantle and to be frank United's winger was blown away by the skill and class of the Brazilian as the Italian side comfortably overcame the Red Devils.
Ferguson says that was a valuable lesson for his side and that they have learned from their mistakes.
They better had because while Barcelona are having a dreadful time in La Liga at the moment, they still have the players who can hurt United in tonight's first leg at the Nou Camp.
After a tough season former Arsenal hero Thierry Henry, likely to be on the bench, would love to show Barca fans what he is capable of while Xavi, Iniesta and Samuel Eto'o are always dangerous. The main threat though to United will come from the brilliant Messi, who is just back from injury.
He knows comparisons with him and Ronaldo will be made, but the Argentine said the outcome of the tie won't revolve around one battle.
"More than a duel between me and Ronaldo, this is a game between two big teams and will be a very interesting match," said Messi.
"I try to do the best I can for my team, but who is better (he or Ronaldo) is something for the people who watch football to decide."
Messi, who missed Barcelona's Champions League success in 2006 through injury, insists his team can beat United.
"We believe in ourselves, we only ask for the people to come along and support us. They are a great team with great players, but we want to keep the ball," he said.
"We also have great players and we are doing everything we possibly can to get to the final and win the trophy."
While Barca, after all their domestic problems, have to raise their game United are oozing with confidence.
They feel it is their destiny to reach the final in Russia and are relishing playing on the Nou Camp stage. After being shackled in last season's semi-final against Milan, Ronaldo is determined to put that right. Alongside him will be Wayne Rooney, who might even eclipse his mate from Portugal and Messi. At the back Nemanja Vidic is set to play after a knee injury.
It promises to be quite a night with United full of belief that it will be a great one for them.