The Sporting boss is said to have already agreed to take over at Old Trafford, which would leave a compensation agreement between the two clubs as the final hurdle. It's claimed he is available for PS8.3million.
In the meantime, Ruud van Nistelrooy will serve as interim manager for Wednesday's Carabao Cup clash against Leicester City.
The 39-year-old has enjoyed considerable success since becoming Sporting head coach in 2020, winning two Liga Portugal titles and two Taca da Ligas in four seasons.
His side are on an early course to become Sporting's first in 70 years to retain the title, having won all nine of their opening league matches this term, scoring 30 goals and conceding just twice.
Amorim has overseen such dominance by perfecting his 3-4-3 system, which he would likely transfer over to United.
It would be a stark difference to Ten Hag's vision, perhaps the inspiration for INEOS' decision to target the Portuguese tactician in the first place.
And while the club's refreshed direction will likely excite some players, others will come under threat after Ten Hag's departure.
Among them is Marcus Rashford.
The 26-year-old has been United's poster boy for most of his eight years as a first-team player, but there is a new age of attacking talent now in the club's ranks.
In Amorim's 3-4-3 system, he uses a winger who can offer speed and strong dribbling and an attacking midfielder who can create chances behind his striker.
Bruno Fernandes, a fellow Portuguese native and United's captain, is almost locked in for the latter role.
Kobbie Mainoo and Manuel Ugarte - who played under Amorim in Lisbon - are the obvious long-term candidates.
Meanwhile, Alejandro Garnacho has been the club's most productive forward so far this season and is widely viewed as the future of the attack.
So where does Rashford lie? Rasmus Hojlund and Joshua Zirkzee better suit the target man-style of frontman Amorim possesses in Victor Gyokeres.
United's No. 10 could almost immediately lose his starting status if Garnacho continues to shine.
