Where the final will be won and lost
Lionel Messi v Cristiano Ronaldo
For many, Wednesday's Champions League final is the unofficial showdown to see which player is the best in the world: Lionel Messi or Cristiano Ronaldo.
Each man is arguably at the peak of their powers and is undoubtedly their respective team's most creative player and man each will hope can unlock their opponent's defence.
Ronaldo is the current European and FIFA World Player of the Year and much will be expected of the 24-year-old when the game gets underway; the question must be whether he can live up to the pressure of star-billing when the stakes are so high.
With eight goals Ronaldo was the top scorer in last year's competition, but he has not scored in his six matches against Spanish opposition and missed an early penalty at the Nou Camp in last year's semi-final first leg against Barcelona.
By comparison 21-year-old Argentine Messi is this season's leading Champions League goalscorer with eight - twice as many as his Portuguese counterpart - but has never scored against English opposition in the 10 games he has lined up against them.
The statistics show that the Barcelona forward has more assists than Ronaldo this season in the Champions League and with five is only one behind joint leaders Xavi and Franck Ribery. By comparison Ronaldo only has two assists to his name.
However, the stats also show that Manchester United man is the more aggressive and appears to be more involved in threats on goal: Ronaldo has had 53 shots, with 32 on target, while Messi has had 24 with 11 on target. But given that the Barca forward has more goals to his name the stats suggests that he is the more accurate marksman, even if Ronaldo appears to be more of a handful.
The task of silencing football's two most exciting and dangerous players is an unenviable one, which could go a long way towards deciding the outcome of the final. So, who's marking who?
Gerard Pique v Cristiano Ronaldo
If, as expected, United line-up with Park Ji-Sung on the right and Wayne Rooney on the left Ronaldo will be utilised as a lone striker, meaning that Barca centreback Gerard Pique is the most likely candidate to be charged with keeping tabs on the Portuguese.
With injuries and suspension decimating the Barcelona defence Pique has become increasingly important and given that he will be facing the team he used to play for the Spanish 22-year-old will be desperate to impress.
Pique has enough pace to keep up with Ronaldo's lightening speed and has enough composure not to dive in and give away cheap fouls. In the air Pique is strong and commanding and more than capable of dominating, but it is with the ball on the deck that Ronaldo poses the most threat thanks to his vast repertoire of tricks and feints.
Lionel Messi v Patrice Evra
Don't let Messi's two subdued showings in the semi-final against Chelsea fool you, he is the player United will fear most. Marked out of the game by a defensive Chelsea side, Messi is likely to be afforded more time and space against United, but that is not to say Patrice Evra will leave the Argentine to his own devices.
Evra will have to keep his attacking instincts in check if he is to nullify Messi; give the Barca forward too much freedom and Messi can turn the game in an instant with his dynamic movement, vision, tricks and pace.
One of the best left-backs in the game Evra is undaunted by the prospect of facing Messi; as he has himself pointed out he faces Ronaldo, Rooney, Tevez and Berbatov in training every week. The Frenchman did a sound job containing the prodigious flair of Theo Walcott in the semi-finals and will be hoping to put in a similar shift at the Stadio Olimpico.
Xavi Hernandez v Michael Carrick
The other key "head to head" area is in central midfield and sees a clash in style between the two creative fulcrums of the United and Barca sides: the tall, athletic Carrick and the diminutive, dynamic Xavi.
With United missing Darren Fletcher through suspension Carrick will be required to shoulder additional responsibility acting as both the defensive shield and creative catalyst.
Carrick is not without his critics, who appear to miss much of the simple but important passes he makes and the vital role he plays in disrupting opposition attacks, but within the United team he is held in high regard. His task on Wednesday will be twofold: to pick the lock of the Barca defence with a pinpoint pass or incisive run while also keeping tabs on his opposite number in the Barcelona ranks.
The heartbeat of the Barca team, Xavi was voted player of the tournament at Euro 2008, and is no less influential for the Camp Nou club. The elegant Catalan mirrors Carrick in that he is as vital to Barcelona in attack as defence.
If Carrick or Xavi manage to dominate their opposite number it could mean the difference between victory and defeat for United in Rome.
Sir Alex Ferguson v Pep Guardiola
The difference in experience between the Barcelona and Manchester United bosses could not be more different: Incredibly Guardiola is at the end of his first season as a coach, Ferguson is at the end of his 35th.
If experience counts for anything Ferguson holds the advantage. He has never lost a European Cup final and will be aiming to join Bob Paisley as only the second man to win the famous trophy three times. If the game comes down to a tactical decision or key substitution it would be a brave man to bet against Ferguson's wisdom holding the key over his vastly inexperienced counterpart.
Having already lead Barca to domestic league and cup glory Guardiola can already reflect on a successful season, but he will not want to end there. Of course, the same is true of Ferguson, who also won the Club World Cup and is just 90 minutes away from a unique quadruple of trophies.
In style and approach both men favour an expansive, high-tempo possession based game - which is why the final has whetted the appetite of neutrals across the world.
If there is a criticism to be made of Barca's approach it could be that they are reluctant to shoot, and appear more interested in creating the perfect move. When it works it is a wonder to behold, when it fails - as it did against Chelsea in the first semi - they can get frustrated.
But both sets of players have great respect for their managers, Ferguson for all that he has achieved and continues to achieve because of his seemingly unquenchable desire for success, and Guardiola for the way he has turned around Barcelona's fortunes in less than a year from La Liga also-rans to a successful, unified squad.