It was all too easy. Two weeks ago the free-flowing football gracing Old Trafford was bamboozling all in its wake, confusing opponents and analysts alike. But after successive matches in which deep-lying opposition defensive blocks kept clean sheets, and the successful Ashley Young-Marouane Fellaini combo failed to make an impact, Van Gaal's meticulously layered dynamics are in need of further tweaking.
West Brom's model is in need of no such work. Comprising of two narrow, tightly compacted lines of defence, Pulis' organisational skills have created one of the strongest defensive shields in the country.
In defeats at Everton and Chelsea, crowded final thirds prevented Fellaini and Young from finding space.
Piercing such armour requires exhausting depths of creative energy, speed and width, and although United possess these characteristics in abundance, their effectiveness is heavily dependent on long ball distribution from the base of midfield – that allows for quick transitions into that overcrowded left-wing position. More intricate methods of incision are required against defensive systems like West Brom's, as Liverpool discovered last weekend in a 0-0 stalemate at The Hawthorns. Brendan Rodgers limited his side's width by positioning Raheem Sterling and Glen Johnson on the left, while Mario Balotelli's movement created a stagnant attack that was easily nullified. The key for United is to build their way through – or around – West Brom's rearguard.
Note how narrow Liverpool were against West Brom; United will need to avoid this mistake.
Full-backs Antonio Valencia and Luke Shaw will be the key components, as is so often the case against ultra-defensive formations; those over and under-lapping runs can pierce through the lines at speed, providing a pass into the box that, with so many behind the ball, is unavailable to attackers.
Pablo Zabaleta is arguably the most adept at these forward movements in the Premier League, but Shaw in particular has shown great promise in this area recently. Young and Juan Mata will find plenty of time on the ball in harmless areas, and it will require sophisticated interchanges out wide to produce the final pass.
