The Red Devils elected not to make a move for the England international this summer as they focused their attention on securing Aaron Wan-Bissaka and Harry Maguire in defence, while Daniel James also arrived from Swansea City.
While all three signings have enjoyed impressive starts to their careers at Old Trafford, Ole Gunnar Solskjaer is keen on bringing in a striker in the winter transfer window.
As reported by Goal, Juventus forward Mario Mandzukic could join for £9 million ($11m), while Tottenham playmaker Christian Eriksen is another target under consideration as the Norwegian also looks at improving other areas of his team.
And the club are already making plans for next summer too, with Solskjaer wanting to continue pursuing young, British talent.
Sancho, perhaps the most impressive English talent around at the moment, has firmly established himself at Borussia Dortmund following his move from Manchester City, with four goals in eight appearances for his club so far this season.
United are keen on strengthening the right side of their attack and improve upon the current options that include the likes of Jesse Lingard and Juan Mata.
Landing Sancho would require an offer in excess of £100 million ($123m) to meet Dortmund’s asking price, with the Bundesliga title hopefuls financially secure but willing to sell at a reasonable valuation.
That fee would not be a problem for United as executive vice-chairman Ed Woodward remains happy to back Solskjaer in the transfer market.
But the sticking point for the Red Devils centres around those advising Sancho, with them being far from convinced that United are a sensible stepping stone in the 19-year-old's career.
While he would be handsomely rewarded in terms of salary, they are aware that the Premier League club's standing in world football is on the decline, and that may not be arrested any time soon as they continue to go through a rebuilding process under Solskjaer.
Dortmund, and any potential rivals for Sancho's signature, hold an advantage over United as things stand, with the offer of Champions League football for next season being critical.
Following Monday night's draw with Arsenal, Solskjaer has overseen the club's worst start to a league season since 1989, with United currently on course to finish outside the top-four spots for the second season in a row.