If ever there was a manager that wasn't the right fit for the club, the Portuguese was it, and it says an awful lot about the board that they've got such a big recruitment decision wrong again.
Amorim's post-match outburst sealed his fate
The manager's own outburst after a disappointing draw at Leeds on Sunday was telling, too.
“I came here to be the manager of Manchester United, not the coach of Manchester United, and that is clear,” he told journalists post-match.
“I know that my name is not Tuchel, not Conte, not Mourinho, but I'm the manager of Manchester United ... I'm not going to quit. I'm going to do my job until another guy is coming here.”
His words, and the manner in which they were delivered, were just about as inflammatory as it's possible to be, and it's no wonder that Sir Jim Ratcliffe and Co. decided to act swiftly.
Try as he might to keep papering over the cracks, Amorim's penchant for doing things his way, come what may, is ultimately what has led the Red Devils to this point.
Sticking to his guns was the wrong choice
Some might say that he deserves kudos for sticking to his guns, because so often in the modern game we see club hierarchy dictating team selection, etc.
Amorim had a clear idea as to how he wanted his teams to play and the personnel to do it, but he just never lived up to the hype that he himself created after a wonderful spell at Sporting.
His evident lack of man-management skills, which saw him alienate the likes of Marcus Rashford, Alejandro Garnacho and Kobbie Mainoo, was troubling, even if he appeared to have the backing of the board in such instances.
West Ham, who had been previously linked with the 40-year-old, might think they've dodged a bullet after such a poor tenure for Amorim at the Theatre of Dreams, and despite any protestations to the contrary, his numbers make for awful reading.
Only West Ham had fewer clean sheets than Amorim's United
For a start, any manager needs a settled side in which to breed confidence and have continuity, and yet the Portuguese made 137 starting XI changes in the Premier League during his time in charge. Only Tottenham Hotspur (155) and Chelsea (141) made more.
Among the ever-present sides in the division from November 24, 2024 - when Amorim took over - only West Ham kept fewer Premier League clean sheets than Man Utd's seven.
The Hammers were also one of only three sides to concede more goals in the top-flight in the same time span. Their 84 is slightly more than Wolves' 81, with Spurs shipping 76 and the Red Devils letting in 72.
For a manager who held great belief in having a back three too, that's a damning indictment of the 3-4-2-1 formation that he used on no fewer than 43 occasions in the league.
The back three just didn't work
With a 3-4-3 also tried on two further occasions, that meant Amorim had used a back three in 45 of his 47 Premier League games in charge, with only Crystal Palace naming more starting XI's (46) with a back three from 24 Nov, 2024 onwards.
Furthermore, of those sides to stay in the division since Amorim's tenure began, only Tottenham (46), West Ham (45) and Wolves (39) have won fewer than United's 58 points.
Things don't get any better for the Portuguese when looking at things from a purely Red Devils perspective either.
Amorim had the second-lowest goals per game ratio as Man Utd manager in the Premier League (1.40 - Ralf Rangnick had 1.38), the worst goals conceded per game (1.53 - 72 conceded in 47 games) and the worst clean sheet ratio (14.9% - seven clean sheets in 47 games).
In amongst the all-time worst Man United managers
Among the all-time Man Utd managers with 50+ games in charge in all competitions, only four have a lower win ratio than Amorim's 38.1%.
They are Herbert Bamlett (April 1927 - Nov 1931, 30.5%), Jack Robson (Dec 1914 - Oct 1921, 31.4%), Wilf McGuinness (June 1969 - Dec 1970, 36.3%) and Frank O'Farrell (June 1971 - Dec 1972, 36.6%).
In fact, in the club's entire English top-flight history, only five managers have the same or a lower win ratio than Amorim's 39.1%.
Robson (31.9%), McGuinness (29.2%) and Bamlett (30.5%) feature again, and they're joined by AH Albut (1889 - May 1900, 20%), Scott Duncan (July 1932 - Nov 1937, 23.8%) and Walter Crickmer (Nov 1931 - July 1932, 26.2%).
Premier League era stats make for grim reading
Looking at the same stats from the Premier League era in all competitions, only Ralf Rangnick's 37.9% was a lower win ratio, but to give more context, Amorim's was the lowest of any permanent United manager in that time.
Even the much-maligned David Moyes managed a win ratio of 50%, and Erik ten Hag posted a figure of 51.8%.
All in all, it's an experiment that has been a complete and total disaster for the club and coach/manager, and only serves to further the disconnect that has festered at United for some while now.
The board simply have to get the next permanent managerial appointment right, or else Sir Jim's dream of winning the Premier League by 2028 will remain just that.
