Both are proving magic off the bench, and Everton has found a difference maker in the big-haired Belgian Fellaini, says Gary Meenaghan.
Best and worst: Javier Hernandez and Edin Dzeko make last impression
Best impression I: Hernandez
Manchester United's Ole Gunnar Solskjaer will for ever be remembered as his club's ultimate "super-sub".
The Norwegian's remarkable habit of scoring during short cameo appearances was never so evident as in the Champions League final of 1999 when he came off the bench to score the winning goal in injury time and complete a dramatic comeback against Bayern Munich.
The most endearing aspect of Solskjaer's character, however, was his willingness to accept the role of impact sub without throwing his toys out the pram.
In Javier Hernandez, United appear to have secured a player of similar ilk. Against Aston Villa, the Mexican scored his seventh goal in five games, yet did so after coming off the bench.
The 24 year old's tireless work rate ensured Sir Alex Ferguson's side won from a losing position for the fifth time this season. Which means he will likely start on the bench again next week, too.
Best impression II: Dzeko
Edin Dzeko's late winning strike against Tottenham Hotspur was his 22nd league goal since signing for City, yet 11 of them, including Sunday night's hooked effort past Brad Friedel, came after arriving from the substitutes' bench.
If Hernandez is the new Solksjaer, then the Bosnian is proving the important impact sub for the blue half of Manchester.
On a weekend when United showed their fighting spirit once again, City had to do likewise. Although they made their fans wait, the result rarely looked in doubt and when Dzeko - who scored four past Spurs at White Hart Lane last season - was introduced, the spectators must have exhaled a collective sigh of relief.
Within 15 minutes of his arrival, City were leading and looking favourably at the table once more.
Best Belgian: Fellaini
Forget Chelsea's £32 million (Dh186.7 m) midfielder Eden Hazard or Manchester City's captain of industry Vincent Kompany.
Forget even Spurs marauding centre-half-cum-fullback Jan Vertonghen, there is only one Belgian this season deserving of consistent praise.
Everton's big-haired playmaker has proved unplayable at times, but it his improved eye for goal that is impressing the most as the Merseysiders continue their rich vein of form.
Last season, Fellaini managed five goals all season. This weekend, after slotting home calmly to gift Everton an equaliser in their 2-1 defeat of Sunderland, he took his tally to six from 11 games.
Such is the 24 year old's confidence at the moment that he is willing to try the audacious and his back-heel that sneaked through the legs of John O'Shea was as audacious as it gets.
The fact Nikica Jelavic was on hand to capitalise and grab the three points was fitting - he is the only Everton player to have as many goals as the Belgian.
Worst assist: Gazzaniga
It is a cruel, hard fact that when goalkeepers make mistakes, they almost always pay for them by conceding a goal.
Hugo Lloris, Tottenham's French goalkeeper, teamed up farcically with left-back Kyle Naughton in midweek against Maribor, but it seems Paulo Gazzaniga, like most, does not bother watching the Europa League.
Southampton's Argentine stopper emulated Lloris by coming comedically together with his defender.
Gazzaniga is still without a clean sheet this season and he did his struggling team no favours when his ambitious pass put Maya Yoshida under unnecessary pressure.
With the ball falling at an awkward height, the Japanese could not control it and Nathan Dyer sneaked in to score a vital equaliser and condemn the Saints to further disappointment.
Worst defending: Arsenal
Arsene Wenger, after much pressure, finally employed Steve Bould at the start of the season as a defensive coach to shore up his Arsenal team's backline. Initially, it appeared a master stroke with the Gunners keeping clean sheets in their first three matches.
After a run of disappointing results since, however, Wenger's side continue to raise questions.
After drawing 2-2 with Schalke 04 on Tuesday, for the second time this week, Arsenal threw away a two-goal lead to eventually draw.
The North Londoners' 3-3 draw with Fulham means their last four matches have now yielded an extraordinary 25 goals.
Wenger's teams have rarely struggled in front of goal, but with Theo Walcott and Bacary Sagna only successfully completing three of their 25 crosses on Saturday, perhaps Wenger will look to bring in another old boy to shore up his wingers.
Freddie Ljungberg, who retired in August, is currently out of work.
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