The 21-year-old tried to push through a move earlier in the month and remains keen the idea of life at Stamford Bridge.
The Blues have spent recent weeks rebuilding their relationship with the Portuguese giants and have this weekend restarted contact regarding their primary transfer target.
Talks had previously failed as Benfica’s frustration grew over offers involving player swaps, deferred payments and reduced fees.
Their stance, ultimately, ended talks after telling Chelsea their player was not for sale unless the full £105million buyout clause was paid.
The demand for the full fee to be paid up-front ended negotiations as it would put Chelsea at risk of Financial Fair Play (FFP) punishments.
Due to accounting rules, buyout clauses cannot be spread over the length of the increasingly long-term contracts being offered by the club, unlike a transfer fee agreed between two teams.
Now, after being accused of driving the World Cup’s Best Young Player award-winner “crazy” by manager Roger Schmidt, negotiations have restarted.
The deal remains difficult but the Blues will try to tempt Benfica into accepting an offer larger than his release clause. That would allow the cost of the transfer to be spread over a seven-and-a-half or an eight-and-a-half-year contract.
Chelsea’s pivot back to Fernandez follows Arsenal hijacking their talks to sign Moises Caicedo.
The Gunners now appear to be in the driving seat for the Ecuador international, who has asked to be sold to Mikel Arteta’s league leaders.
The Blues are keen to complete their business by signing a midfielder before deadline day, having also expressed an interest in Brighton’s Alexis Mac Allister and Everton’s Amadou Onana.
Chelsea have already spent almost half a billion pounds across the last two transfer windows after signing £26m Malo Gusto yesterday, before loaning him back to Lyon for the rest of the season.