Unlike in Rome two years ago, Sir Alex Ferguson has no Cristiano Ronaldo to call upon, no Carlos Tevez to spring off the bench but Manchester United still possess the personnel to upset the Champions League favourites.

Having conceded just four goals in 12 Champions League outings this term, defensively, Manchester United have been sound in Europe but on Saturday they come up against one of the most formidable attacks in world football.

Ferguson is likely to field the same 4-4-1-1 formation which led his side, in the latter part of the league campaign, to their record 19th title, although the Scot has been known to tinker with his line-up for the big occasions.

But the biggest problem United will encounter at Wembley will be the possession game. Pep Guardiola’s charges have enjoyed 89% pass completion rate at the Camp Nou and 90% away from it – a mesmerising statistic when you think just how teams have enough time to win the ball back, get it into Barcelona’s half and launch a successful attack.

 

Manchester United - Barcelona: The influential figures and factors at Wembley

 

So who and what will be the influential figures on Saturday?

Xavi, Barcelona metronome, has averaged just under 107 passes per game in Europe this term. The Spaniard dictates the rhythm, instructs the direction of play and keeps Guardiola’s side ticking over. It’s the base of their possession game.

How Real Madrid countered this was to stand off Xavi when he has the ball and allow him to pass, but as soon as the ball was played, the receiving man was swamped by two shirts. But this is where United will come unstuck if they play a 4-4-2. Jose Mourinho’s 4-5-1 allowed three central midfielders to scuttle among Barcelona’s core, denying space. With two in midfield, United are in danger of being overrun by the trio of Andres Iniesta, Xavi and Sergio Busquets.

Wayne Rooney will need to keep his positional discipline at Wembley. It’s imperative the England international resists the urge to stray too far from his likely attacking partner Javier Hernandez. With the Mexican isolated, United will have little hope of breaking down Barcelona, therefore Rooney will need to strike the balance between dropping deep to receive the ball and combining with Hernandez to attack.

Sergio Busquets also plays an important role in picking up Rooney. Neither Gerard Pique or Carles Puyol can track Rooney when he drops towards the centre circle as this will leave a one-one-one situation with the sharp Hernandez. Instead, the communication needs to be there for Busquets to sit and deny Rooney room to operate in. In the same breath, Rooney needs to display the awareness of knowing hen Barcelona have lapsed in picking him up and exploiting that mistake.

A weakness for United will be at right-back. Ferguson has the choice between the experience of John O’Shea, or the young guile of Rafael. The Scot may be inclined to pick the former, as the Brazilian has sometimes shown ill discipline, United cannot afford in a game of such magnitude.

A way of suppressing Barcelona can come from the flanks. It’s likely Ferguson will favour the industry of Park Ji-Jung on the left, while Antonio Valencia’s recent form perhaps pips Nani to a spot on the opposite flank. Whoever the two wingers are, they will need to give Dani Alves a problem defensively, along with the likely selection of Eric Abidal on the left. Park’s work rate may also persuade Ferguson to give the South Korean a starting berth as he is able to track the runs of the Brazilian, as well as coming inside to stifle Barcelona’s midfield.

Dealing with Lionel Messi is another issue Ferguson will have to contend with. The Argentine floats between flanks, making him elusive to a marker. It’s difficult to deploy a man marker whose sole job is to disrupt the game of his opponent. United have this player in Darren Fletcher, but in order to build up attacks of their own, Ferguson must strike the balance between players who are an asset defensively and personnel who can contribute significantly to an attack.

This is why the United boss may opt for the central-midfield pairing of Ryan Giggs and Michael Carrick. The Welshman’s season has been outstanding and his experience in the middle should prove vital. Carrick, meanwhile, one of the best United’s best passer in Europe with a completion rate of just over 88%. A player who can link up with the defence, refuse the long ball option and retain possession will be vital against a side like Barcelona who thrive on keeping the ball.

Largely, however, it’s likely Ferguson’s charges will be chasing the ball for the majority of the encounter. But if Ferguson’s side hold their nerve, and counter attack with pace as they’ve shown both domestically and in Europe this term, this should make for one interesting match.