The 21-year-old left Old Trafford over the summer after failing to make a single competitive appearance for Man United during his four years at the club, having signed from Real Madrid in 2020.
Man United recouped €6m (£5m) through selling Fernandez, who has gone on to establish himself as a regular during his first full season at Benfica whom he joined on loan for the second half of last season.
The left-back has already made nine appearances in all competitions during the 2024-25 campaign, after managing one goal and one assist in 16 games during the second half of last term.
Fernandez's performances are believed to have attracted glances from both Barcelona and Real Madrid, although Man United reportedly have until 2026 to activate their buyback option for the Spain Under-21 international.
Liverpool 'stalking' Fernandez amid Real, Barca competition
However, even though the Red Devils are currently in a crisis at left-back - which could see Jonny Evans play in that position against Brentford this weekend - they are not thought to have any immediate plans to recall Fernandez.
Instead, AS reports that Liverpool have shown the 'greatest interest' in signing the 21-year-old next year, having been 'stalking' Fernandez ever since he touched down in Portugal.
Before swapping Man United for Benfica, Fernandez enjoyed a fruitful loan spell at Preston North End, setting up six goals in 42 matches during the 2022-23 season before a short spell at Granada.
Thanks to his previous exploits in England, Liverpool apparently have no concerns about how Fernandez would be able to adapt to Premier League football, although he is still contracted to Benfica for another five years.
Fernandez's deal with the Eagles is also understood to include a release clause, as well as Man United's buyback option, but it is not known how much a club would have to pay to trigger the former.
Fernandez to replace Andy Robertson at Liverpool?
For the past seven years, Liverpool have had very few worries about the left-hand side of their defence, as Andy Robertson has developed into one of the top players in his position in Europe since joining from Hull City.
However, the Scotland international is now in his 30s and is out of contract in the summer of 2026, so it is only natural that Liverpool are going to start planning for the future without Robertson.
Perennial backup Kostas Tsimikas is not expected to take on the role of first-choice left-back when Robertson eventually departs either, but Liverpool are said to have already run the rule over two potential candidates.
Rennes' Adrien Truffert is rumoured to have emerged as a leading target, and following the Paris 2024 Olympics, the Reds supposedly made contact over signing Lanus and Argentina youngster Julio Soler.