Alexis Sanchez arrived at Old Trafford to much fanfare and acclaim with United having acquired his services in a stunning, eleventh hour swoop from under the noses of Pep Guardiola's City.
I'm sure I wasn't alone in being the most hyped about a United signing for years - here we had one of the finest exponents of his craft at the peak of his powers. A man whom had earned a reputation as one of the best in the Premier League for his swashbuckling exploits at Arsenal and a bundle of energy, skill and creativity. Not only did it make for comedy gold on AFTV but the Reds had acquired a genuine world class talent and a showman player who seemed a natural fit for the Old Trafford stage. Even his unveiling, with the suave Sanchez tinkling the ivories to the tune of Glory Glory Man United, got the pulses racing. No new player had ever been announced like this. If his time at the club was even half as good as the build-up, then we were on to a winner. Or so we thought. But all of this could not have been further from the truth.
Now, 31 months on, the Chilean has made his loan switch to Inter Milan a permanent move, linking up with former United team-mates Ashley Young and Romelu Lukaku at the Nerazzurri. Sanchez will be quickly forgotten at Old Trafford, and will hold the dubious honour of one of - if not THE - worst signings in this club's proud and illustrious history. It has been a disasterclass.
His signing certainly divided opinion. There's a very valid argument to be had that when a world class players becomes available, as indeed Sanchez did, then you should go all out to get him. But United didn't need him, Marcus Rashford and Anthony Martial were playing well and Sanchez upset the applecart. His signing ruined the wage structure and caused resentment among the players, particularly those longer-serving stalwarts on money nothing like as good. The board saw the pound signs in front of their eyes. Here was a chance to sell shirts, push "brand United" to a new level and acquire another big name, big money X Factor signing. Ed Woodward simply could not resist the temptation. It was another failed transfer, another black mark.
The best paid player in the league, on astronomical wages of £475,750 a WEEK, departs with only five goals to his name in 45 games - against the might of Huddersfield, Swansea and Newcastle in the league and two in the FA Cup against Spurs and former club Arsenal. The Sanchez who left the Gunners was not the Sanchez that joined United and just about everything that could go wrong did indeed turn Pete-tong.
So how did one of the most sought-after players on the planet become Old Trafford's biggest flop?
He did score on his home debut and his form in that first half a season was not a complete failure. But after that, Sanchez was poor and his form deserted him to the extent that United have since emphasised their need not to repeat mistakes made with the Chilean - even when pursuing players such as Jadon Sancho.
There was no doubt that Sanchez was a versatile player, capable of playing on the left, on the right, down the middle or as no.10.
But whilst he had a clearly defined role in north London as Arsenal's string pulling creator in chief, at Old Trafford there was confusion. The chemistry was different, he never nailed down a regular position and displaced the in-form Martial, throwing the mercurial Frenchman off his game and effecting his confidence. Even when deployed out wide at Arsenal, Sanchez had Olivier Giroud ahead of him with Mesut Ozil as the creator. He could not have wished for more willing team-mates. At United, only Juan Mata fitted that bill and he was never a regular at that point. Sanchez was expected to add creativity despite being the one who often relies on it from others.
Sanchez was coming into a defensive team, not Sir Alex Ferguson's vintage. Mourinho's concerns over the side's defence meant there was rarely an overlapping full-back and Mourinho's emphasis on safety first meant that he was never given the space nor the freedom to shine. Not entirely his fault, but in hindsight his was a signing that went against Mourinho's raison d'etre.
I don't mind players losing possession - you're never going to be successful with every pass and it often means you're trying to make things happen and taking risks. Even the best players cough up the ball from time to time. Bruno Fernandes as an example. But Sanchez seemed to do so more than most and earned unwanted headlines in games against Huddersfield and Newcastle when he squandered possession 36 times on each occasion - no doubt the nadir of his days at Old Trafford. He had fewer touches in the opposition box and dropped deeper to receive the ball, attempting more dribbles as a result - perhaps in an insight into his carelessness on the ball.
He never seemed fully fit and always looked a shadow of his former self. Never has there been such a dramatic decline in a player in such a short space of time. Four goals in 25 games for Inter hasn't exactly hinted at a renaissance.
Sanchez departs as just another disappointment - albeit a very expensive one. He's cost United over £40m in wages alone. Another example of the malaise that gripped the club in the years after Ferguson's retirement. Inexplicable? There were clues, glimpses, of why this was not a good fit, and more that could have done to make it work. But nobody could have foreseen quite how badly Sanchez's move would go.