Marouane Fellaini exemplifies turmoil and turnaround at Manchester United

As Marouane Fellaini strolled off the field in the 83rd minute, to be subbed out for Radamel Falcao with Manchester City long since vanquished, Old Trafford rose to its feet to give the midfielder his due recognition. For a solid minute they clapped as the afro-topped Belgian returned to the Manchester United bench.

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You would have bet large amounts of money on a fair few improbable things happening before Fellaini got a standing ovation in Manchester. But it's been two weird seasons at United, and nobody exemplifies the turmoil and turnaround better than Fellaini, who nodded home the go-ahead goal and won the ball back for United's third in a 4-2 derby win on Sunday.

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He'd come over from Everton with new manager David Moyes just before the summer transfer deadline in 2013-14. At $42.5 million, the midfielder was Moyes's only significant summer buy, after many weeks of wrangling with Everton – which caused United to miss the window for his minimum transfer fee, ultimately costing the club a few extra millions. But it turned out to be one of those moves that left everybody a loser. Fellaini made just 15 starts last season. The Daily Telegraph named him one of the 10 worst buys of the season. The Daily Mail spoke of Fellaini's "Manchester United nightmare." The Mirror called it his "nightmare year."

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When Louis van Gaal succeeded Moyes, who had lived through his own nightmare spell, he cleared out much of the existing team and seemed to have little regard for Moyes's squad-building efforts. Had it not been for an ill-timed ankle injury – or perfectly-timed, as it may turn out – Fellaini would have been playing in Italy this season while on loan at Napoli. He was going to be shunted off, discarded as an expensive write-off.

In that sense, he sort of embodied Moyes's brief and unhappy tenure as Sir Alex Ferguson's successor. It was a time the club and Van Gaal kind of wanted to pretend never happened by removing all the vestiges thereof, players included.

But Fellaini hung around, recovered from his injury and did enough to get himself back into the first team. He didn't make his first start until October 26 of this season, against Chelsea, but he contained the red-hot Cesc Fabregas and his injury-time header allowed Robin van Persie to score the equalizer off the rebound.

From then on, he became a fixture with long stretches as a starter. When Fellaini snuck to the back post to head home Ashley Young's soft cross on Sunday, it was his third Premier League match-winner since January 17.

Van Gaal won't like to admit it, but United's resurgence has coincided with its renewed willingness to play direct soccer. And Fellaini has allowed them to do that. Where to put him on the field has always mystified coaches, as he doesn't have a skillset that's easily equated to a particular position. But as a high-attacking midfielder in possession, as he was at Everton, he allows United to play long. Up there, his six-foot-four frame and the six added inches of hair knock down balls for others to pick up and get the attack going.

Fellaini's increased importance to the team – he has been absolutely foundational to its recent success – must on some level vindicate Moyes. So does Juan Mata, a January buy by Moyes who was marginalized during the first half of Van Gaal's season. The latter beat Hart one-on-one for the third goal on Sunday and has been instrumental in United solidifying a top-four finish.

And then there's Ander Herrera, whose transfer fell through under Moyes only to be completed the summer Van Gaal arrived. It may well be the case that this move had been sealed prior to the appointment of the Dutchman, and the reluctance to use Herrera for many months, before being swayed by his current form and deep influence, suggests as much.

Ashley Young, likewise, has played his way into Van Gaal's team – contributing two assists on Sunday – after a tentative first few seasons at the club. While Van Gaal is now being called a genius for turning the club around – and he certainly deserves a great deal of credit – the players who have delivered the points for him were not the ones he spent hundreds of millions on this summer.

Fellaini – and Mata, and maybe Herrera – will be glad for that. The failures of Angel Di Maria and Radamel Falcao to live up to their hype and price tags created job openings. And Van Gaal can't really complain about how things are transpiring, either.

Leander Schaerlaeckens is a soccer columnist for Yahoo Sports. Follow him on Twitter @LeanderAlphabet.