Fellaini, 26, became a star at Goodison Park after his £15m switch from Standard Liege in 2008, and his impressive displays on Merseyside eventually led to his big move to Manchester United in September 2013, following David Moyes from Everton to Old Trafford.
But whilst Moyes saw Fellaini as the answer to the Red Devils' midfield woes, the Belgian has struggled to make an impact this season, looking far from worth the £27.5m that United paid to land him at the start of the campaign.
With United needing a lot more in midfield, some had speculated whether Fellaini could be sold at the end of the season, with a return to Everton tentatively linked - but manager Roberto Martinez says that Fellaini wouldn't even get in his team now, as the Toffees are well stocked in midfield.
"You look at [James] McCarthy, [Gareth] Barry, Leon Osman - where would Fellaini have fit? In football you move on so quickly. I'm just happy with the squad that we have. And James McCarthy would never have happened if Marouane didn't go. I've just been proud of the squad," said Martinez, who has guided Everton to the brink of Champions League football this season.
Fellaini's struggles have been well documented this season, but Martinez still believes that the towering midfielder will prove his worth eventually, given his success as a player before his spell at United began.
"I think you take a little bit of time to adapt to a new club and it's not easy. Remember that it's always a different way of playing your football in many respects," said Martinez.
"I think that Marouane has always shown that he's a winner. He's a player who will find a way to be successful. That's what you want to believe with him," he added.