Sir Alex Ferguson may move Wayne Rooney to cover the left, man-mark Cristiano Ronaldo and play on the counterattack
Manchester United's shape could be similar to the system they used against Everton on Sunday, with Phil Jones pulled over to the right to help counter Cristiano Ronaldo, and United's left-sided midfielder playing very narrow. That may mean Wayne Rooney covering the left, as he did against his former club. Ferguson has used him there in previous contests of this magnitude, at Camp Nou in 2008 for example. The former Liverpool right-back Alvaro Arbeloa is not particularly dangerous in an attacking sense, but he still requires attention.
Alternatively, if deployed in his usual central position, Rooney will be asked to close down Xabi Alonso and prevent him spraying diagonal passes to the flanks – either way, he must show defensive discipline, and then burst forward quickly at attacking transitions.
José Mourinho has used various shapes and systems over the years, but Porto, Chelsea, Internazionale and now Real Madrid have all been devastating on the counterattack. Real are superb at turning opposition corners into profitable attacking situations, with the trio of Ronaldo, Mesut Ozil and Angel di María particularly dangerous on the break.
United should be cautious about attacking in great numbers – leaving the full-back positions unoccupied is a very dangerous tactic at the Bernabéu, while Ozil's creative threat, plus Ronaldo and Di María's tendency to cut inside and shoot, makes it imperative the back four is protected.
Robin van Persie and Rooney might have to fend for themselves, with a sporadic counterattacking threat from the flanks.
Two individuals have dominated in league wins over United this season – Gareth Bale of Spurs and Everton's Marouane Fellaini. In both return fixtures, Sir Alex Ferguson has successfully deployed Jones in a specific defensive role to stop the opposition's primary threat turning in a repeat performance.
Ferguson does not need a demonstration of Ronaldo's attacking flair to realise he requires special attention. The Portuguese winger starts on the left before cutting in and shooting powerfully from long range – he averaged 6.2 shots a game in the group stage – and Jones is the best player to support Rafael da Silva, replicating the right-sided, defensive-midfield role he played against Bale.
Darren Fletcher's performance, shuttling back to help Gary Neville cope with Ronaldinho in a 4-0 win over Milan at this stage three years ago, is another good template.
But Da Silva's individual contribution is also vital. Against particularly dangerous opponents the Brazilian usually sticks tight and tracks his man across the pitch – so Antonio Valencia must follow Real's left-back, either Fábio Coentrão or Marcelo, on overlapping runs.
Ronaldo is Real's greatest individual but Ozil is an astoundingly talented, selfless playmaker who varies his positioning superbly, gently easing opponents out of position before knocking casual but penetrative passes through the gaps. His movement from central zones towards the flanks allows Ronaldo and Di María to move inside, and his decision-making when attacking directly is faultless.
Michael Carrick will be the player in closest attendance, but marking Ozil too tightly will leave United undermanned in midfield. Instead, Carrick must communicate effectively with the back four, and be brave enough to let Ozil go free when he moves into advanced positions. Minimising the space between the lines, rather than insisting on remaining goalside, is Carrick's best chance of stopping him.
Pepe and Sergio Ramos are among the finest defensive pairings in Europe – strong in the air but mobile on the ground, and capable of bringing the ball forward. Both prefer to stick very tightly to opponents, and if United use two strikers against them, with both moving deep towards the ball, Rooney and Van Persie may be able to draw the Real centre-backs out of position before exploiting the space in behind.
Rooney and Van Persie have both performed impressively this season without directly combining as a partnership particularly frequently, but this is a good opportunity for some intricate link play - think Andy Cole and Dwight Yorke at the Nou Camp in 1998/99.
Michael Cox is the editor of tactics website zonalmarking.net