Ole Gunnar Solskjaer is keen to add a creative midfielder to his squad during the January transfer window as he aims to find consistency in results and performances at Old Trafford.
Tottenham schemer Christian Eriksen and Leicester City talent James Maddison had emerged as the club's primary targets, but it now seems unlikely either will be making their way to the Theatre of Dreams this month.
Eriksen is expected to complete a move to Inter as he enters the final months of his contract at Spurs while Leicester are not contemplating selling England international Maddison until the summer at the earliest.
The Red Devils have also been linked with Newcastle's Sean Longstaff but, with the 22-year-old having rejected them during the summer, the 20-time English champions are reluctant to waste their time with another offer in such a short space of time.
United have, in turn, been forced to go back to the drawing board, and Goal has learned that they are now considering going back in for Fernandes having shown an interest in the Portugal international in the summer of 2019.
Fernandes was linked with a number of Europe's top clubs following a season in which he scored 32 goals and provided 18 assists for Sporting, with the player himself revealing that Tottenham came closest to prizing him away from the Portuguese capital .
He signed a new contract with Sporting in November that runs through until 2023 and saw his release clause increased to €100 million (£85m/$111m).
United are yet to make any contact with Sporting regarding a potential transfer, but there would be no difficulty from United's end in raising the funds required to sign the 25-year-old should Solskjaer make it clear that he needs to be acquired in January.
The interest in Fernandes comes in the wake of United planning an aggressive scouting mission in Portugal, with the club sending representatives to every game being played by Porto, Benfica and Sporting in the coming weeks in a bid to identify potential targets for both January and the summer transfer window.
United have never undertaken such an assignment, which suggests they are having to quickly reconsider their options with the January window now having been open for almost a week.
As well as their disappointment in pursuing Eriksen and Maddison, United have been left reeling by Erling Braut Haaland's decision to join Borussia Dortmund from Red Bull Salzburg.
Haaland had emerged as United's primary target for the January window, but the Norway teenager instead opted for the Bundesliga outfit as RB Leipzig also showed an interest.
Wolves forward Raul Jimenez has now emerged as a potential target, with initial talks under way , but Mario Mandzukic, who was also on Solskjaer's radar, is now unavailable after leaving Juventus for Al-Duhail in Qatar .
Further back in midfield Jimenez's team-mate at Wolves, Ruben Neves, is being considered with Paul Pogba and Scott McTominay both facing spells on the sidelines.
Their injuries have also meant that Nemanja Matic will see out the season at Old Trafford, though it is understood he sees his long-term future in Italy.