When Memphis Depay signed for Lyon in January 2017, he left Manchester United's number seven shirt empty.
The number is one which carries particular resonance at Old Trafford, but how did that come to be?
Squad numbers were introduced in English domestic football in 1993, but players were associated with a number a long time before that.
Long before there was Zlatan Ibrahimovic and Anthony Martial, there was Willie Morgan and Georgie Best...
When Morgan arrived at Old Trafford in 1968, he had a particular request for United's legendary manager Sir Matt Busby.
In his autobiography "Willie on the wing," Morgan wrote:
"Then Sir Matt said, "Well it's all sorted and we are happy with the fee, but is there
anything you would like to ask me?"
Well, I have always worn the No. 7 shirt," I replied.
"No problem," said Mr Busby, "You can have the No. 7 shirt and we'll
give George the No. 11 shirt.
I know he won't mind."
Best is often included in the list of legendary United no. 7s, but he was as much associated with 11.
However, he did sport 7 when United won the European Cup in 1968.
Bryan Robson carried both the No. 7 and United in general on his back throughout the 1980s.
This was pre-squad numbers, of course, but Robson
was nonetheless breaking from tradition in an era
where numbers were defined by roles on the pitch rather than personal brand association.
Captain Marvel was not an outside right, but in importance and aura, he was every inch a "United number seven."
He was also humble enough to surrender his claim on it with the advent of the age of
squad numbers, and the age of Eric Cantona. Collar up and chest out, everything about Eric was iconic.
The number did not make him iconic, he made the number iconic.
Then came David Beckham and an endless procession of haircuts and devastating assists.
Beckham became associated with "Cool Britannia," with
his image seen far beyond the world of football.
Beckham said of the number ""It was never my shirt.
It was George Best’s, Bryan Robson’s, Eric Cantona’s.
“The only reason I wanted to wear the No.7 shirt was because of these players."
According to Roy Keane in part two of his autobiography "The Second Half," Beckham was lucky to end up with it.
"‘The manager pulled me into his office and said that he wanted me to wear the '7'.
'I said, ‘No, I’m not that bothered.'
'And he said, "I know Becks will want it and I don’t want him to have it."
In then end, of course, as Keane wrote. "Becks got it. It suited him."
When he left for Real Madrid Beckham cited Michael Jordan as his inspiration for the choice of number 23.
Raul was Madrid's untouchable No. 7 at the time.
To take his shirt would have been heresy.
​And then came United's last great number seven. Cristiano Ronaldo, given the shirt at just 18 years
old, after his 12.24 million pound transfer from Sporting Lisbon.
Robson, Cantona, Beckham, Ronaldo —a remarkable series.
Unfortunately Michael Owen was Ronaldo's underwhelming replacement.
Then came Antonio Valencia, bumped up from No. 25 to No. 7 in the wake of his player's
player of the season award in 2011-12.
Eventually, the Ecuadorian asked for his old shirt back, telling MUTV:
"It had been something I had been thinking about for quite a long time.
I'd been considering a change back and maybe it is psychological
or maybe it is just all about a good-luck symbol, if you like.
We get a lot of that in Ecuador, maybe superstition, and l hope it continues and still brings me
more good luck this season."
Good luck has continued to elude the seven shirt ever since.
Angel Di Maria may have been a match talent wise, but never seemed happy in Manchester.
Memphis Depay barely got a chance.
Whoever is next, they have a lot of history to live up to