Chelsea are trying to land Argentinian World Cup winner from the Benfica for a reported fee of 120 million euros (£105.5m).
The previous record was set by Manchester City following the signing of Jack Grealish for £100m in August 2021.
However, Chelsea could also make a late bid for Brighton’s Moises Caicedo, who has been linked with Arsenal for much of the last month.
The south coast club turned down Arsenal’s initial £60m offer, and have since been adamant the Ecuador international will remain at the club for the rest of the season.
But Fernandez is likely to be the latest in a string of new arrivals at Chelsea, who have spent over £450 million on transfers since the conclusion of last season.
Data collected by Seatpick.
1. Jack Grealish - Aston Villa to Manchester City - £103.3m
Jack Grealish moved to Manchester City in the summer of 2021 when Guardiola's team triggered his release clause from Aston Villa. (Picture: Michael Regan/Getty Images) Photo: Michael Regan
2. Romelu Lukaku - Inter Milan Chelsea - £99.4m
Romelu Lukaku moved to Chelsea from inter Milan back in the summer of 2021 but has been returned to Inter on loan (Picture: Clive Rose/Getty Images) Photo: Clive Rose
3. Paul Pogba -Juventus to Manchester United - £92.3m
Manchester United £92.3m to bring Paul Pogba back to the club from Juventus back in 2016. The French World Cup winner is now back at Juventus. (Picture: PAUL ELLIS/AFP via Getty Images) Photo: PAUL ELLIS
4. Antony - Ajax to Manchester United - £83.6m
Manchester United bought the Brazilian international from Ajax in the Netherlands in the summer of 2022 (Picture: Catherine Ivill/Getty Images) Photo: Catherine Ivill