The 20-year-old joined the Red Devils from Real Madrid in 2020, but he has yet to make a competitive appearance for the senior side.
Fernandez gained valuable playing time during a loan spell with Preston North End last season, featuring in 39 Championship matches for Ryan Lowe's side.
Having returned to his parent club, Fernandez was involved in Man United's preparation for the new season, appearing in four pre-season friendlies against Leeds United, Lyon, Wrexham and Athletic Bilbao.
However, the youngster does not appear in Erik ten Hag's plans for the 2023-24 campaign, with the likes of Luke Shaw and Tyrell Malacia currently above him in the pecking order.
There was an expectation that Fernandez would leave the club on another loan deal, but it seems that Man United would be open to parting ways on a permanent basis.
According to The Mirror, the Red Devils will listen to offers of £6m for the Spaniard, who has attracted interest from Burnley and West Ham United.
Burnley are currently light in the left-back area after Ian Maatsen returned to Chelsea following the conclusion of his loan deal at the end of last season.
Meanwhile, West Ham are also looking to strengthen the left side of defence, with Aaron Cresswell believed to be heading towards the exit door.
In a separate report, Relevo reveal that West Ham and Burnley are facing competition from clubs in Spain and Germany for Fernandez's signature.
Newly-promoted Granada and Las Palmas have both been linked, while Espanyol are keen to add Fernandez to their squad as they look to mount a promotion push after being relegated from La Liga last term.
In Germany, Eintracht Frankfurt are showing an interest in Fernandez, who has a contract with Man United until June 2024 with an option to extend by a further year.
Man United still believe that the full-back has a long-term future at the elite level and will look to include a buy-back clause in any sale.