Current and former Manchester United players back incoming head coach Amorim
Amorim must hit the ground running in one of the most scrutinised jobs in football that saw Erik ten Hag fired on Monday - the latest of five permanent managers who have wilted in the shadow of United's most successful boss Alex Ferguson.
But those who know the Sporting coach, considered one of Europe's brightest young managers, insist he will be a big improvement as he has the charisma and ability to connect with players which is a pre-requisite for success.
"I spoke to (former United and Sporting player) Nani a few days ago and he said to me: 'Rio, the players play for him, they love him and respect him,'" former United and England defender turned pundit Rio Ferdinand said.
"United need someone with the character and charisma to go 'You know what? I don't care what has happened here, I see a player in you.' You need someone who is going to be like that."
Amorim, whose appointment was announced on Friday, will join United on November 11th, with his first match slated for November 24th at promoted Ipswich Town in the Premier League.
The two fixtures that follow are Norwegian team Bodo/Glimt in the Europa League and a home Premier League game against Everton, which should provide a positive start.
But then he faces two big away tests, at Arsenal on December 4th and champions Manchester City in a December 15th derby.
All five permanent managers at United since Ferguson retired in 2013 arrived to plenty of optimism and solid starts before fortunes turned in a cycle of rinse and repeat, Old Trafford's Theatre of Dreams becoming the stuff of nightmares.
Amorim is considered a hero at Sporting, pulling the club out of the doldrums by winning two Primeira Liga titles, the first of which, at 36, was the club's first title in 19 years.
He already has fans at United in the shape of two Portugal players Diogo Dalot and club captain Bruno Fernandes.
"He is a fantastic coach and knows what he wants. Very demanding is what I can expect. It's a perfect match for a club like this," full-back Dalot told Sky Sports.
"The Premier League suits people from Portugal. We have a culture of constantly trying to improve ourselves as we come from a small country. I really hope that it is one more case. I am really excited to start working with him."
One of United's glaring weak spots this season has been the inability to put the ball in the net, with only Southampton and Crystal Palace scoring fewer goals this season.
Amorim has no such offensive issues with Sporting, who have a three-point lead atop the standings with their 30 league goals being seven more than their closest opponents Porto.
Sporting's 26-year-old Sweden striker Viktor Gyokeres has scored 12 times in nine games and may well be on United's radar.
Amorim, however, inherits a squad in which 70% of the players were chosen by Ten Hag, who spent over 200 million euros on players in the close season.
They have not been living up to their price tag and United's ownership is clearly stinging, part of the reason perhaps that Amorim was named United's first 'head coach' and not manager.
"Manchester United managers have had too much power. Ruben Amorim, or managers in the future, won't get that," former Liverpool defender turned pundit Jamie Carragher said.
"The club has to make the right signings for the manager, whereas Erik ten Hag picked exactly who he wanted regardless of the money - 85 million pounds for Antony, it hasn't worked out.
"Casemiro, they shouldn't be paying 70 million pounds for a 30-year-old midfielder."
How much United's co-owners INEOS will loosen the purse strings after Ten Hag spent more than 600 million pounds on players since his arrival in April 2022, coupled with five consecutive years of financial losses, remains to be seen.
With United competing in the League Cup - where they visit Tottenham Hotspur in the quarter-finals next month - the Europa League plus the Premier League and the FA Cup, Amorim can gauge what he has got before the January transfer window.
Carragher believes he can win with the current group.
"One of the reasons the United job is so alluring right now is because every top coach working in Europe will have been watching their games for the past 15 months and believed they could organise the same set of players to perform much better," Carragher said The Telegraph.
"There is talent there with no evidence of world-class coaching to get the most from them."