The Red Devils are expected to confirm the appointment of Amorim on Thursday after striking a deal with Sporting to hire the Portuguese, whom they will pay just over £9m for.
Man United are believed to have triggered the £8.3m release clause in Amorim's Sporting contract, and the 20-time English champions will also pay an additional £840,000 for the 39-year-old's coaching staff.
Amorim's move to Old Trafford initially hit a snag due to a 30-day notice period in his Sporting deal, but the final details are now being ironed out for him to take charge of Man United after the international break.
The 39-year-old was not the only option on Sir Jim Ratcliffe and INEOS' shortlist, though, as The Athletic reports that three other high-profile head coaches came under consideration to replace Erik ten Hag.
Xavi, Edin Terzic among previous contenders for Man United job
The report claims that three available managers - Xavi, Edin Terzic and Massimiliano Allegri - were discussed within the Old Trafford walls, and the process to hire any member of the trio would have been less complicated than negotiations with Amorim.
Xavi left his position as Barcelona head coach following a 2023-24 soap opera, in which he publicly announced his resignation midway through the campaign and insisted for months that nothing could change his mind.
The 44-year-old eventually had a change of heart and agreed to stay, but he is then said to have irked president Joan Laporta with comments made about Barca's financial situation and left his post after all.
It was claimed that CEO Omar Berrada flew to Barcelona to hold talks with Xavi, but negotiations never reached an advanced stage, and the same goes for ex-Borussia Dortmund boss Edin Terzic.
Meanwhile, Allegri - who left Juventus in disgrace at the end of the 2023-24 season - was 'looked at', but Man United concluded that the 57-year-old could not build for the future in the same manner that Amorim could.
Which Sporting players could follow Amorim to Man United?
Amorim's successful spell at Sporting has seen the 39-year-old help produce some notable names, including Paris Saint-Germain's Nuno Mendes and Man United's Manuel Ugarte, whom he will soon reunite with at Old Trafford.
A recent report has claimed that the Portuguese wants to bring as many as three players from the Estadio Jose Alvalade with him, including English winger Marcus Edwards, a former Tottenham Hotspur academy graduate.
Fellow attacker Pedro Goncalves and defender Goncalo Inacio have also apparently been identified as two men who could thrive in Amorim's system, and the 39-year-old's arrival at Old Trafford has naturally led to suggestions that Man United could jump to the head of the queue for striker Viktor Gyokeres.
The Sweden international has struck a terrific 59 goals in 65 games since joining Sporting from Coventry City, although Arsenal and Manchester City are also expected to be in the mix for his signature in 2025.