Sancho has been widely linked with a return to England this summer, with clubs like Liverpool, Chelsea, and Manchester United all thought to be yearning to sign the former Manchester City man.
The England international has been one of the best players in Germany and a deal to sign him could cost £100m, according to several media reports.
Sancho has scored 31 goals in 91 appearances for Borussia Dortmund since joining the Black and Yellows in the summer of 2017.
Hargreaves has insisted that securing the services of Sancho would be a coup for Ole Gunnar Solskjaer’s men and at the same time it will help the 20-year-old to become a better player.
"Jadon will know his own game and has to find what’s best for him,’ the ex-Bayern Munich man told BT Sport.
"But United have an exceptionally good group of young players coming through – and any top young player would want to be part of that.”
"Obviously, Liverpool and Manchester City have moved away from everyone else in the Premier League, but United would still be a team to join.”
“Things go in cycles. Man United will be back and the recruitment of a player like Jadon would help.”
"He knows Manchester well because he was at City, but whoever gets him will be very fortunate. I know Sancho is going to cost a lot of money, but you have a player who, potentially for the next decade, is going to be a unique player to watch.”
"Can he become a Ballon d’Or winner? Yes, because potentially he is off the charts. The impact he has had already has been quite astonishing."