There were times at Old Trafford on Tuesday night when Manchester United shifted seamlessly into a very attacking 4-2-4 formation. It was made possible by the presence of one man in central midfield, a large, deceptively awkward looking Belgian of Moroccan heritage with wonderfully unruly hair.
Marouane Fellaini's 11th-hour, £27.5m importation from Everton made him the first central midfielder signed by United for six years. This rather startling statistic perhaps explains why, during the final years of Sir Alex Ferguson's tenure, he became such a fan of assorted forms of the five-man midfield while easing up on some of the thrillingly high-calibre gung-ho stuff that once so distinguished him from the pack.
If the 4-2 Champions League win over Bayer Leverkusen represented the first real occasion David Moyes has forgotten he is supposed to be a pragmatist while occupying Ferguson's old seat, this philosophical watershed could not have happened without Fellaini.
With the 25-year-old holding central midfield alongside the much less spiky Michael Carrick, United were free to base their gameplan around an essentially 4-4-2 system in which Wayne Rooney was regularly in an attacking partnership with Robin van Persie.
With Leverkusen adhering to the Champions League norm and deploying five midfielders in that familiar 4-2-3-1 shape – which may, incidentally, become a bit passé and less voguish as the fashion cycle moves on again this season – Moyes's tactics would have been suicidal in Fellaini's absence. With him around, United's advanced quartet had freedom to improvise without too much inhibiting fear about being caught on the counterattack.
The Belgian is strong and powerful enough to make the two-strikers-plus-two-wingers equation work. Nothing is perfect, though, and the worry must be that using Fellaini this way may cramp the creativity of a player who finished last season as Everton's top scorer with 12 goals.
No one is saying he should return to his sometime role at Goodison Park where he proved capable of filling Tim Cahill's old second striking role in a generally much more direct, pragmatic and set-piece reliant Everton ensemble. But if United's new manager consistently picks so many attackers in front of Fellaini we may not see enough of his potentially devastating box-to-box raids. Let alone goal-scoring from midfield.
As his partnership with Carrick develops more of that may be possible – particularly in certain fixtures – but the suspicion lingers that United, especially if they want to keep playing this way, could do with recruiting an authentic central midfield water-carrier capable of tackling when necessary in January. Quite apart from offering an alternative to Carrick, the newcomer could facilitate alternative gameplans – including inter-match switches from 4-4-2 to 4-2-3-1 or 4-3-3 for instance – thereby adding variety to Fellaini's repertoire.
Moyes, though, may be content with the cards he already holds. He has said he believes the man he brought to Everton from Standard Liège five years ago is best deployed deep in central midfield. Having excelled at running the 10,000m as a child, the near 6ft 5in Fellaini clearly possesses the necessary stamina. Equally important, his aerial ability affords Rio Ferdinand and friends added protection. Against Bayer Leverkusen Fellaini won a few important defensive headers.
The best player in a very good Belgium side needs to refine only parts of his game to look the polished United professional. As well as he largely played on Tuesday there was a sense of much more to come from the expensive new boy. There were more misplaced passes than he or Moyes would ideally want and he allowed Simon Rolfes too much space before he shot Sami Hyypia's team back into the game.
It was all part of a brief United wobble, a minor detail in the bigger picture but against more ambitious opposition a high price might have been paid for that error.
No matter, it is early days and Fellaini is honest enough with himself to tweak his game and approach where necessary. "I have a problem with the intensity of the training at United because I am playing with big players," he has said. "It is quicker than it was at Everton. But I am happy."
It is unlikely to take him long to get fully up to speed. Then United fans should really see the emergence of what used to be commonly known as "a midfield colossus". The term might have been coined with Fellaini in mind.
Downsides? Well, Everton fans will say that their team tended to look defensively weaker when Moyes shifted the Belgian forward and infinitely less menacing when he dropped him back.