Sir Alex should play with 4.5 midfielders (I will explain the 0.5 soon). Now to deal with the Messi/Villa threat, you need to deny them direct access to your back four. You need to clip them (yes, literally) all the time. Which means you plant a “cleaner” in front of your centre-backs to mop up any crumbs left from the process of flushing out attack waves. I am referring here to a JS Park or Darren Fletcher, preferably Park, considering the speed with which Barca attacks through the middle. To counter Park’s erratic but effective style will be a Michael Carrick, who comes with the added feature of being a good ball distributor. So Park cleans, Carrick distribute, easy. In 2009, Park started against Barca in an attack right position, disastrous! This time, he should be made to replicate the role he played in the quarter-final games against Chelsea: a neutralizing holding midfielder.
Now on the flanks, United should not go for full-time wingers. In modern football, a full-time winger is tied down with work along the flanks all game, and barely contributes to central midfield play. Thankfully, Giggs has grown (or rather aged) into a full-midfielder nowadays and Valencia is brave enough to take the entire midfield on his own! So that makes 4 midfielders. The 0.5 is the boy Wayne Rooney. He will be United’s number 9.5: a deep-lying centre-forward. Helped by his physical strength, he will be difficult to pick out since he will neither be in the face of Pique nor in the midst of Iniesa or Xavi. With Rooney lurking in a deep-lying centre-forward position, Busquet will be wary of running forward in attack and wrecking his usual supply damages. And in case Keita plays for Barca, he is likely to behave the same way, as Barca’s central midfielders will have their backs to Rooney, with the threat of him supplying a difficult-to-catch Hernandez.
Rooney will lend his other half in attack to support Hernandez. Hernandez is matured enough to stay on his own, with his speed being his main weapon. Pique is good, but may not be quick enough to outrun Hernandez. Rooney’s other half, as well as Valencia and Giggs coming in from the flanks, could turn the Mexican into a hero on the night, especially Valencia’s crosses (and potential ability to deal with Eric Abidal). Having studied United this season, Guardiola will certainly be smart enough keep an eye on the Mexican. This gives opportunities in a counter-attack situation for Rooney, Valencia, Park or Giggs to pop up with a goal.
Whatever you do Fergie, just don’t go to Wembley and defend all night!