If Ruben Amorim had been granted his wish, he would still be in Lisbon now, eyeing up a two-week January break and trying to guide Sporting to a third title under his watch, a perfect parting gift before his summer move to Manchester United.

At Old Trafford, Ruud van Nistelrooy would still be enjoying the buzz of being caretaker manager. The bounce he elicited from United, along with a system the players were comfortable in, might have nudged the club towards the top half of the table.

Instead, Van Nistelrooy has a mighty relegation battle on his hands at Leicester City, and one of the clubs he is trying to catch his former one, who have gone from a bad season to one where relegation is being mentioned as a possibility. Amorim's mid-season arrival and his drastic change has made things worse before they get better.

READ MORE: 'A lot to answer for' - Jamie Carragher identifies who is to blame for Manchester United mess

READ MORE: Tyrell Malacia 'offered' Man United transfer escape route - but there's a catch

But then the 39-year-old head coach saw all this coming. When United approached him about replacing Erik ten Hag in November, he wanted to wait until the end of the season. He felt he had a job to finish at Sporting, but he also knows that significant change is more straightforward to push through with a summer transfer window and a full pre-season stretching out ahead of you.

Speaking after United had made their move, but while he was still Sporting CP boss, Amorim said: "I had three days to decide one option that radically changes my life.

"The only request I made was for it [the transfer] to be at the end of the season, and they [United] told me that it wasn't possible; that it was now or never. I knew if I rejected it that in six months I wouldn't have it. And I knew that in six months I would know that I wouldn't be at Sporting."

Amorim had already told Sporting that this was his final season. It was shaping up to be a glorious one, but United's move stopped it in its tracks. At the time, it felt like United had acted like a big club should, demanding they get their man now rather than wait another eight months.

In hindsight, should they have listened to Amorim? Spending most of the season with a caretaker might feel like a waste of time, but Van Nistelrooy was delivering results and was a safe pair of hands. He didn't rip up the 4-2-3-1 system of Ten Hag. Instead, he tweaked it, he made changes to the team and he delivered an improvement.

Amorim's change has been much more drastic, and these players clearly don't fit his demands. Five defeats in six Premier League games leave United precariously placed, and any outside chance of European qualification through the league has vanished. Amorim is learning nothing now that he couldn't have picked up in the summer if he had started at Old Trafford then.

As for Sporting, Amorim's good work has started to be undone. They are now top only on goal difference, and four of the first five games after his departure ended in defeats. It was so bad that Amorim's replacement, Joao Pereira, has already been sacked, dismissed on Boxing Day after just eight games in charge.

A new year is a time for new starts, but it might have suited both United and Sporting, not to mention Amorim, Van Nistelrooy, and Pereira, to have stuck with the status quo until the end of the season. It looked like United were doing the right thing in pushing for Amorim to come immediately, but the evidence of the past few weeks suggests otherwise.