Felix only joined Chelsea from Atletico Madrid in the summer for £45m as part of the deal that saw England midfielder Conor Gallagher move the other way.
But sources have told talkSPORT the talented Portuguese international is unhappy at his lack of playing time after starting just three of Chelsea's 23 Premier League games.
That has opened the door to a potential late-window exit, with Villa boss Emery a huge admirer of Felix having also tried to sign him before his Chelsea switch.
Chelsea are also one of the clubs on the trail of Villa's £80million-rated Jhon Duran to bolster their striking ranks, so do not rule out Felix being part of another player-exchange.
Man United star could be sold
Rasmus Hojlund was previously viewed as one of the few players Manchester United would not entertain bids for.
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But that stance looks to have changed and Hojlund will effectively find himself on trial between now and the end of the season.
The Dane is enduring a miserable season having scored only two league goals and gone 11 Premier League matches without hitting the back of the net.
talkSPORT has been told hard-line United boss Ruben Amorim has been far from convinced by the £72m man.
That news has filtered to Italy with Napoli and Juventus among the clubs keeping a keen eye on the situation.
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If United did decide to sell the 21-year-old they would have to take a significant hit on what they paid Atalanta to sign him at the insistence of Amorim's predecessor Erik ten Hag.
In total, Hojlund has 23 goals and three assists in 71 appearances in a Red Devils shirt.
Potter wants striker reunion
West Ham's striker search if expected to run to the final hours of the window.
New boss Graham Potter has made it clear to the Hammers' hierarchy recruiting a new No.9 if a must after losing Niclas Fullkrug to injury.
The London Stadium outfit have as many as TEN forwards on their list of potential targets, with Evan Ferguson right at the top.
West Ham believe they are favourites to sign Ferguson IF he is allowed to leave Brighton on loan but the ankle injury that has seen the Irishman miss the last six games is an issue.
talkSPORT understands the Hammers have already agreed personal terms with Brian Brobbey on a £100,000-a-week deal but have so far been unable to agree a deal with Ajax.
Initial conversations have also been held with RB Leipzig over Portugal star Andre Silva, but Ferguson is the one Potter really wants having worked with him at Brighton - although the striker also has interest from Bournemouth, Tottenham, Everton and several European clubs.
England star's transfer U-turn
One player who looks unlikely to be returning to England this month is AC Milan centre-back Fikayo Tomori.
Three Lions international Tomori has been on the radar of several Premier League clubs including Tottenham, West Ham and Aston Villa.
It was thought earlier this month that Tomori was looking for an escape route from the San Siro after falling out of favour with former Milan boss Paulo Fonseca.
But he has become a regular starter under Fonseca's replacement Sergio Conceicao and sources close to the 27-year-old say he is now happy to stay.
Watch Ruben Amorim's brutal response when asked about Marcus Rashford's absence from Manchester United's win over Fulham