Former outcast Fellaini may hold the key to United beating City

He's always effective for Mourinho.

This season, Manchester United fans have learned how to stop worrying and how to love Fellaini. For long stretches of his time at the club, the Belgian has found himself scrambling to remain in the supporters' good books. Granted, it's never been cool to like Fellaini but, over time, fans have gradually joined Jose Mourinho in The Cult of Marouane. Let's take it back to last year, when Fellaini was an Old Trafford outcast. His popularity plummeted after a bumbling cameo against Everton when, with United leading 1-0, he conceded a penalty three minutes after coming on as a late substitute, clumsily sticking out a leg and fouling Idrissa Gueye. Fellaini, a former Everton man of course, couldn't hide from the torrent of abuse he endured on that return to Goodison Park, but he would have been justifiably crestfallen to hear boos coming from his own supporters during his next appearance, as he was heckled after replacing Ander Herrera a week later against Tottenham. Although Mourinho has always defended him, there was a lingering sense that Fellaini's days at United were numbered. When he was linked with a move away in the summer, it looked like a foregone conclusion. But he stayed and, not only did he stay, he has since scurried his way back towards acceptance and, dare I say it, popularity. Fellaini has had his injury woes this season and, even when he's been fit he hasn't been a guaranteed starter. But Mourinho likes what the Belgian has to offer: physicality, an aerial threat in the opponent's box and generally being a nuisance to defenders. Mourinho sees in Fellaini an on-pitch extension of his own more nefarious tendencies, a man who revels in frankly pissing the opponent off. Let's face it, Mourinho has always embraced the Machiavellian side of football management. But Fellaini is more than just Mourinho's muscle. When he has played he has usually been effective. He scored twice against Crystal Palace, bagged the opener against Basel after he replaced an injured Paul Pogba and also netted after coming off the bench in the win over Leicester. There's no enigma to Fellaini. He's awkward and clumsy, all fuzzy hair and flailing limbs, but he works. It's easy to figure him out but, as defenders have discovered, stopping him is another matter. He will work against Manchester City, too, if he's fit. After the win over CSKA Moscow on Tuesday evening, Mourinho said there is 'a chance' that Fellaini could feature against City. Although United can still beat City without him, Fellaini is the perfect player to cause their rivals all sorts of problems in the box. Mourinho may look to exploit Fabian Delph at left wing-back with either Jesse Lingard or Anthony Martial, but the Portuguese coach will know from his homework in recent weeks that City don't do height very well. Angelo Ogbonna scored a header against them last weekend, easily beating Nicolas Otamendi in the process. The Argentine actually had a solid game against the Hammers - which included scoring the equaliser - and is by no means an easy man to beat, but Mourinho will be confident that his side can dominate in the air with the height and aerial prowess he has at his disposal, even in Paul Pogba's absence. With an eight-point deficit to overcome, this is a game United can't afford to lose but it would be a fool's errand trying to out-pass this City side on the ground. No, United's likeliest chance of three points will come via the tried-and-true method of getting crosses in from wide and, with Fellaini and Romelu Lukaku to feed, there's major potential in that route. With Ashley Young's crossing ability, Fellaini will get chances if he plays (two of his four goals have come from finishing off Young's deliveries). Back in April 2015, Fellaini scored a header against City from a Young cross. United fans will be hoping for that same connection come Sunday. But even if he isn't there, the presence of Lukaku, or even Nemanja Matic, Chris Smalling and Marcos Rojo from set-pieces, could be enough to unnerve a City back-line that looks shakier without John Stones. Even with Vincent Kompany, Mourinho will feel the heart of defence is where the chink in City's armour lies. If Fellaini plays, expect him to be in the thick of it, giving City plenty of headaches (and no, we don't mean by elbowing them to the temple). Even if doesn't make it, though, it's been a remarkable turnaround for the 30-year-old. From being the lumbering scapegoat of last season, he has developed into one of Mourinho's key men - and he may have the opportunity to prove as much when they take on Guardiola's pacesetters on Sunday.