Both players have been persistently linked with moves away from Goodison Park; primarily to Manchester United.
A few current articles, such as Mark Ogden's in The Telegraph, suggest that United will now focus primarily on Fellaini. But Sam Wallace's piece in The Independent, which claims Baines is keen on leaving, will set alarm bells ringing among Evertonians.
In an ideal world, neither player departs, but losing Baines would be a catastrophic blow for the Toffees, especially at this late stage of the transfer window.
The diminutive left-back has been Everton's best player for several seasons. Despite lining up in defence, it's in the final third where he makes his biggest contribution, frequently bounding forwards on the overlap and looking to create.
His end product is as accurate and reliable as it comes in the Premier League, which has seen him become a creative marvel going forward, supplying a constant stream of ammunition to his forwards.
Unless used in the right way, statistics can sometimes be a lazy way of highlighting a player's impact, but with Baines it's very necessary to help distinguish his supremacy.
Last season he created a staggering 116 chances, the most among any player in the Premier League. That's even more remarkable when his position is remembered, as he fashioned out double as many chances as any other recognised defender.
Baines also delivered 353 crosses last year, at least 50 more than any other player, and was rightly awarded Everton's Player of the Year, an honour he's becoming familiar with.
All this shows exactly how central he is to the Toffees' play and, unsurprisingly, Baines also recorded more touches than any other Everton player last season, showing this significant influence. As a result, the Toffees' left flank saw possession 42 percent of the time last season, the highest proportion in the Premier League, as Everton continually looked for his input.
Losing this much creative power and this much of an integral feature would clearly jeopardise the Toffees' approach this coming campaign, and could potentially even derail it. With so many attacks passing through Baines at some stage, Everton would be a far lesser force without him, putting added pressure on new manager, Roberto Martinez.
While the Spaniard will be looking to evolve his new club's style, Baines is still likely to be its primary feature.
His Wigan side were similarly reliant on crosses from Jean Beausajour last season, who delivered the fourth most (254) in the top flight. Overlapping full-backs are also a prominent characteristic of his system, and Martinez has been quick to announce his excitement at working with Baines.
Having such attacking influence from left-back is rare and something Martinez would find difficult enough replacing if given an entire summer, let alone the last few days of this transfer window.
In short, selling Baines at this late juncture would be seriously damaging to the Toffees, and the club's hierarchy must do everything in their power to prevent his departure.
If financial restraints demand one marquee player goes, it must be Fellaini.
Statistics via WhoScored?