Fernandes has made clear to West Ham that he wants to leave following the club's relegation to the Championship, with a move to Old Trafford his stated preference.
United pulled out of the race for Nottingham Forest midfielder Elliot Anderson once it became clear Manchester City were leading that pursuit, and have since redirected their focus entirely to Fernandes.
According to the Mirror, Manchester United are confident there will be no issue agreeing personal terms with the player, who is keen on the move and is attracted by the club's return to Champions League football next season.
West Ham United's position, however, remains firm.
Decision makers at the club regard Fernandes as one of the most talented young midfielders in England and have placed a valuation of around £80 million on him.
West Ham signed Fernandes from Southampton for around £40 million last summer, and believe his performances since arriving in east London justify a significant premium on that fee.
According to Sky Sports, the Hammers are in no rush to sell and would prefer a bidding war between multiple clubs to drive the price higher.
Paris Saint-Germain and Real Madrid have both been linked with the player, though transfer journalist Fabrizio Romano reports that Real Madrid's interest has not advanced significantly given how many midfielders they already have following the arrival of Bernardo Silva.
Romano has stated that West Ham's asking price remains around £85 million, with United working to bring that figure down.
United are said to be preparing an opening bid in the region of £70 million, hoping West Ham's need to generate transfer revenue following relegation gives them some leverage in negotiations.
Michael Carrick's coaching staff have discussed Fernandes in depth and believe his ability to operate across the width of midfield — combining pressing energy with technical quality on the ball — makes him the ideal partner for incoming Atalanta midfielder Ederson.
For Fernandes, the situation is straightforward.
He is 21, he wants Champions League football, and he wants to join United specifically.
What remains to be resolved is whether the two clubs can close a gap that currently stands at somewhere between £10 and £15 million — a difference that will test the resolve of both sides as the window progresses.