The former Manchester City winger has become one of the continent's emerging superstars this season, shining for Borussia Dortmund as they streaked clear atop the Bundesliga in the autumn.
Sancho remains the top assist-maker in Europe, level with Lionel Messi, and has 11 Bundesliga goals to boot in a breakout campaign for the teenager winger.
Any thoughts Ed Woodward had of an easy ride in signing the 19-year-old forward have been dashed by reports emerging from Germany that Madrid are also keen, with the £100m mooted asking price unlikely to scare off either club.
Madrid and United are the world's two richest (and arguably biggest) clubs so the prospect of a bidding war will delight Dortmund as they look to use any fees from the Sancho deal to further fuel their youthful rebuild.
Zinedine Zidane is on the lookout for two forwards as part of his Real Madrid refit this summer, with Eden Hazard already pegged for one of those spots. Gareth Bale is unwanted, with the Frenchman already having told president Florentino Perez to take a financial hit on the Wales winger by either selling him for a cut price or loaning him out.
Sancho would help the Bernabeu club reduce their average age considerably, one of their key objectives in this summer's rebuild, and they have followed Sancho for a number of years having nearly signed him in 2017 when he elected to move to Dortmund in search of first-team action. Madrid do, however, have other players at the position that they are monitoring including Luka Jovic of Eintracht Frankfurt (on loan from Benfica) who has been another of the season's big revelations at centre-forward.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies