Amorim will officially begin his reign at Old Trafford on November 24 away to Ipswich Town at Portman Road, but will go into that game without one of his players.
United defender Victor Lindelof hobbled off the pitch during Sweden's 2-1 win over Slovakia on Saturday.
Despite his 266 appearances for the Red Devils, fans would know the centre-back has struggled for match time this season, playing only 58 minutes through four substitute appearances in the league.
Most likely, Amorim does not intend to start the Swede but with injury worries Lindelof could have possibly upgraded his role within the side.
As the Portuguese coach prefers a back three, automatically one centre-back will rise into the first team.
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New signing Leny Yoro, Lisandro Martinez and Matthijs de Ligt are the expected to form his long-term new back-three.
Unfortunately, Yoro suffered a foot injury in pre-season against Arsenal and is yet to make his first competitive appearance for the Red Devils.
Meanwhile, Martinez missed out on international duty with Argentina and will need to have his fitness assessed after picking up an injury against Leicester City.
Harry Maguire would also have been competing for minutes and eyeing a starting spot under the new manager, but the Englishman is also recovering from a foot injury.
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That leaves Jonny Evans as the main benefactor, having made an appearance against the Foxes as a substitute ahead of Lindelof, who did not touch the pitch that game.
Amorim, possibly with a makeshift backline, has a huge job on his hands to unite the fans with the squad.
It's a task he started without stepping foot in England, beating Manchester City 4-1 in the Champions League in his final European match as Sporting boss.
Despite being announced on October 28, fans will have to wait until November 24 for Amorim to be on a Premier League touchline when they face Ipswich Town at Portman Road.
What seems to be an easy three points but after Ipswich's first win of the season against Tottenham Hotspur - a team placed higher in the table than United - it may be a tougher task than expected.
Fans hope the 39-year-old will trump the stint of Erik ten Hag who was heavily criticised for a lack of style.
They were delighted to hear Amorim's first interview with the club as the Portuguese coach said: "I think you will see an idea. You could like it or not, I don't know, but you will see an idea.
"You will see a positioning. You will see something that we want to reach that kind of level. You will feel that. I will do evertything for the team... I will try to do everything to put this club in the place that it belongs."