It's not hard to see their point. Pep Guardiola's team have run us dry of superlatives since he took over in 2008, inflicting their triumph of tici taci on a seemingly endless number of inferior opponents who've tried to stand in their way - like hapless henchman sent to an altogether predictable death.
Playing Barca these days usually results in one of two fates. Either you're blitzed in a blur of blaugrana, or you're starved of oxygen in a war of attrition that ends with a well-timed blow to the head.
Lionel Messi, David Villa, Andres Iniesta, Xavi and Co. are among those armed with the weaponry to deliver it. And unless you find a way to nullify their combined threat, while at the same time summoning the requisite energy to chase Spanish shadows for 90 minutes, you're done for.
Or at least that's what Jose Mourinho thought. Drawing on the stifling tactics that helped his inferior Inter Milan team past Barca last season, The Special One entered into a four-game El Clasico series convinced of his adage that you don't need the ball to win the match.
But the two games that mattered most proved him wrong. Real Madrid exited the Champions League at the hands of a far more adventurous and positive opponent, who managed to score two times in the Bernabeu despite Madrid focusing their entire effort on keeping a clean sheet.
Manchester United will not make the same mistake at Wembley. Sir Alex Ferguson is too proud of United's heritage, and too aware of the implications to his own reputation, to send out anything another than an attacking formation against Barcelona. An ethos must be protected.
Attack is the United way, and the club and its fans will simply not countenance a stifling exercise against the team most consider the most exciting in the world. Sometimes it's better to lose than win ugly.
But United may not have to settle for either. If Ferguson can get his team playing with the dynamism they displayed in the first leg against Schalke in Germany, Barcelona will be stretched to contain them.
The key for United is setting a tone for the contest in the first 30 mins.They did it in Rome, when the two teams met in the 2009 final, but United failed to capitalise with a goal. If they can score early at Wembley the game could be theirs for the taking.
The contributions of Antonio Valencia and Nani, assuming both start, could prove decisive. If United can press high up the field on the flanks and force the Barca full-backs to defend, the momentum will be theirs. And if that in turn affords Wayne Rooney greater room in front of the back four, United have the beating of Barca.
Another reason for optimism is that compared to 2009, Ferguson's brood are now more of a team. In Rome everything was centred around Cristiano Ronaldo, and when Barca found a way to stop him, United came to a standstill. The2011 vintage may be weaker without him, but they're arguably harder to police.
One final reason to believe United can beat Barcelona is the man who'll be sitting in their dugout. Providing United avoid defeat against Chelsea, Ferguson will have led his team to a record 19th title, and should enter the final calm and focused, and with nearly 25 years of experience behind him.
Meanwhile, Guardiola will probably still be dealing with the fallout of the draining battles with Real Madrid. The 40-year-old's calm facade has been breached, and let's not forget the pressures of coaching the supposed best club side of them all.
Most would disagree, but I see United winning it 2-1.