Throughout 2012-13 Wigan Athletic have posed a unique tactical challenge in the Premier League, as the only side to have regularly fielded a three-man defence.
Roberto Martínez turned to the unusual 3-4-2-1 formation when Wigan were bottom of the table in February last year, when five points off 17th, and following an excellent run of form in the new system they finished comfortably in 15th place. It was so successful primarily because it was simply something different – when playing the Latics, opponents found themselves with a problem they'd forgotten how to solve. This season the novelty has worn off and Wigan's alternative system is no longer a surprise. In recent weeks Martínez has also encountered significant problems with injuries at the back – Ronnie Stam, Maynor Figueroa and Iván Ramis are all unavailable for the FA Cup final, while Antolín Alcaraz is doubtful and Gary Caldwell regularly depends upon taking two pain-killing injections, having not trained properly for six months because of a hip injury.
With so many centre-backs unavailable Martínez has reverted to a back four, although Wigan still attempt to play in a style befitting a three-man defence. In Tuesday's 3-2 defeat to Swansea, Emmerson Boyce, Caldwell, Paul Scharner and Roger Espinoza were theoretically the four defenders. On the pitch, it was something entirely different – the full-backs pushed extraordinarily high up the pitch – Espinoza looked defensively shaky, but opened the scoring – while Ben Watson played very deep, as a forward-playing sweeper rather than a holding midfielder. The result was something unusual – almost a 2-1-4-3 in possession.
Last season Martínez explained why he moved away from a back four in the first place. "When you play a 4-3-3 you rely a lot on the full-backs to get high up the pitch," he said. "When you want to be very attack-minded, the full-backs have to push on, so you leave [only] two players at the back." That's precisely what Wigan did against Swansea, and something similar may be suicidal against City.
Wigan's are naturally adventurous and positive in possession, and they focus their passing down the left flank. Shaun Maloney will drift inside to central playmaking positions, dragging Pablo Zabaleta out of the defence, while the energy of Espinoza – or Jean Beausejour, if fit – means Roberto Mancini will select James Milner on the right for his defensive commitment. On the other flank Callum McManaman will stay high up the pitch, but Gaël Clichy will attempt to intercept passes played towards him, and launch quick counterattacks.
Unusually for an underdog, Wigan will be most vulnerable on the break, especially as Manchester City showed their counterattacking ability in a terrific end-to-end semi-final victory against Chelsea. If Martínez continues with the shape he used on Tuesday night, Watson's role in front of the defence – sitting deep and breaking up counters – will be crucial to Wigan's chance of nullifying City.