The winger is currently on loan at Aston Villa but remains contracted to United only until June, meaning he is set to become a free agent unless a late change occurs.
After difficult spells in the Premier League, Sancho is now believed to be targeting a move back to Germany, where he previously produced the best football of his career.
The Sun report that Sancho wants to return to Borussia Dortmund**, with the Bundesliga side also interested in bringing him back for a third spell.
The report claims talks have already taken place between the player and Dortmund, with financial details discussed as both sides explore the possibility of a summer reunion.
Dortmund boss Niko Kovac is also said to have approved the move, leaving senior club figures to decide whether to complete a deal for the soon-to-be free agent.
Sancho first joined Dortmund from Manchester City in 2017 and quickly developed into one of Europe’s most exciting young attackers.
During his first spell in Germany, he scored 50 goals and registered 64 assists in 137 appearances, form that earned him a £73million move to Manchester United in 2021.
However, the England international struggled to reproduce that level at Old Trafford, managing only 12 goals and six assists across 83 matches.
His time at United was further damaged by a public falling-out with former manager Erik ten Hag in 2023, leading to his exit from the first-team picture.
Loan spells at Chelsea, Aston Villa and Dortmund followed, but only his return to Germany during the second half of the 2023-24 campaign brought signs of revival.
Sancho scored three goals and added three assists in 21 appearances as Dortmund reached the Champions League final that season.
This term at Villa, he has managed one goal and three assists in 33 appearances.
With his United contract expiring and Dortmund open to a reunion, a permanent move back to the Signal Iduna Park now looks one of the most realistic outcomes of the summer window.