This time last year, Marouane Fellaini was the poster-boy Manchester United's failings under David Moyes; his cumbersome technique and awkward build symbolic of the Scot's disturbingly attritional philosophy, his £28million arrival from Goodison Park a case-in-point of how Moyes had 'Evertonised' the 13-time Premier League champions - at least, in the eyes of the Red Devils fan base.

A new season and a new manager however, and it's an incredibly different story. Combining his opener against QPR on Saturday with an equaliser against West Brom and a galvanising strike against Stoke City, and that's seven points from United's 40 the Belgium international can lay considerable claim to - not to mention a series of influential performances, particularly against Crystal Palace, Arsenal, Southampton and Liverpool, along the way.

But what's changed so dramatically for Fellaini in the space of a calendar year? What's the secret behind his rise from Old Trafford boo-boy to Manchester United's most impactful centre-mid? Why has he become so important to Louis van Gaal's first season at the club?

Fellaini's effectiveness in the Premier League has never been in doubt, even amid the tribulations of last season. Although unorthodox and often ugly on the eye, the aerial dominance of his 6 foot 4 frame causes problems for opponents in both penalty boxes, whilst his combative nature serves equally well against the division's top and bottom clubs, where Manchester United's physicality, work-rate and resolve is tested most.

Of course, the major question mark lingering above the 27 year-old's iconic afro last term was whether he possessed the technical and creative qualities to be successful at a club like Manchester United. A lack of both remains a significant hindrance - I'm yet to witness Fellaini go a full game without committing unforced errors in possession - but the difference this season is how his strengths are being emphasised instead.

Last term for example, Darren Fletcher, Marouane Fellaini, Tom Cleverley and Michael Carrick finished up with just two goals and one assist collectively, creating only 50 chances to score - in comparison, Chelsea's Cesc Fabregas has already registered 65 single-handedly this season. Limited flair and poor technique was symptomatic of the entire engine room, but the Belgian lankster was the biggest culprit, contributing the least chances and averaging the fewest forward passes per-match of all four.

Statistically, there's been almost no change from last season - chances increasing from 0.31 per-match to 0.46 and forward passes dropping from 30.5 to just 24 - but Fellaini is now surrounded by midfielders prepared to do that for him. Carrick, Ander Herrera, Wayne Rooney, Angel Di Maria, Juan Mata and even Daley Blind all exceed upon the 27 year-old's chance creation whilst their tidiness on the ball, boosting United's average possession from 55.3% last season to 58.7% this season, is already well established.

Resultantly, instead of epitomising the intrinsic weaknesses of United's engine room, Fellaini has become its predominant source of variety. The technical talents surrounding him allows the Belgian to play his own game and in turn, he provides a sense of directness and dynamism going forward that the others can't. That unique diversity has become Manchester United's 'plan B' under van Gaal this season and, rather tellingly, two of the 27 year-old's three goals in the Premier League have come from the bench.

And in my opinion, it's no coincidence that the towering midfielder's influence has soared during the Dutchman's first season in English football. Barring left-back Luke Shaw, all of United's summer signings were foreign, as is their new manager, their newfound 3-5-2 system and of course, their new philosophy. Experienced Premier League personnel remain but none embody the unique physicality, directness and competitiveness of the English top flight quite like the Belgium international; for any underestimations or misinterpretations van Gaal's made regarding the Premier League, Fellaini's now serving as the perfect remedy.

Whether Fellaini's United career will span much further remains to be seen. Although he's proved effective in a rather unique capacity this season, it's not one that will serve the Red Devils particularly in the long-run - especially if a tough-tackling, goal-scoring, dynamic presence of the Kevin Strootman or Arturo Vidal mould is signed during the summer.

Between now and May-time however, a run of games that will decide whether the van Gaal revolution has succeeded or failed, the preservation of Fellaini's productive form could have a huge impact on United's Champions League bid.