The 19-year-old made 22 starts for Wednesday before moving to fellow Championship side Norwich in the winter transfer window.
He played just once for his new club before suffering a season-ending hamstring injury.
With Manchester United searching for a new left-back themselves this summer, Amass is keen to secure regular game time back in the Championship next season rather than compete for minutes at Old Trafford.
Amass is under contract until next year, with the deal including the option of a further one-year extension.
United are expected to include him in their provisional pre-season squad, having left him out of last year's tour party ahead of his anticipated move to Wednesday.
Despite his preference for a loan, well-placed sources have not ruled out the possibility of Amass staying to provide competition for Luke Shaw at left-back, with the pair potentially set to rotate in United's pre-season friendlies against Wrexham and Rosenborg in July.
Amass joined United from Watford's academy in 2023 and made his first-team debut in a 3-0 win over Leicester City in March 2025. He has gone on to make seven senior appearances and impressed during the club's 2024 pre-season tour of the United States, establishing himself as one of the more promising young defenders in the squad despite his recent injury setback.
A second loan spell in the Championship would give Amass the chance to rebuild momentum after a frustrating end to last season, with regular senior football seen as more valuable to his development at this stage than fighting for a fringe role in United's first-team squad.
The club's left-back position remains unsettled heading into the new campaign, with Shaw facing the prospect of a reduced contract and United still exploring the market for additional options at the position.