Despite the impressive goalscoring form Anthony Martial, Marcus Rashford and Mason Greenwood have shown, Ole Gunnar Solskjaer has been keen to bolster his options up front.
If United secure his signature, the 20-year-old is expected to take his place on the right-hand side of the front three with Rashford on the left and Martial through the middle.
The England international has been a revelation in the Bundesliga since leaving Manchester City three years ago.
This past season, Sancho scored 20 goals and provided 20 assists.