Callum Hudson Odoi's brother, Brexit and the persistence of Bayern Munich.
It's thanks to this triple threat that highly-rated teenager Jamal Musiala is currently strutting his stuff in the red of Bayern Munich as opposed to the blue of Chelsea.
The 17-year-old midfielder was the recent subject of an international football tug of war, with Germany ultimately winning the tussle ahead of England. German domestic football had also come out on top 19 months earlier when Musiala opted to switch Stamford Bridge for the Allianz Arena, leaving Chelsea after eight years in the club's academy.
He has gone on to become Bayern's youngest Bundesliga player, Bayern's youngest Bundesliga scorer and the Champions League's youngest English goalscorer in the space of eight months - leaving Blues fans cursing the one that got away.
However, this is not a regretful, Declan Rice-esque tale of release and redemption. Musiala was not let go by Chelsea - the Blues were eager to offer the teenager a professional contract, but he simply could not resist the offer from the biggest club in the country of his birth. While Chelsea did not 'throw the kitchen sink' at Musiala, Bayern were persistent, and he turned down the west Londoners' professional terms to sign with the Bavarian giants.
Musiala initially played for Southampton's Under-8s, before being scouted by Chelsea. The youngster first pulled on a Blue shirt for the same age group in a friendly against Blackburn and instantly caught the eye with his ability to go round players.
He was frequently ahead of his peers and playing up an age group during his time at Cobham, featuring for the Under-18s just a couple of months after celebrating his 15th birthday. Although his technical ability was what stood out, this was matched by his work rate and winning mentality.
"I remember we played Spurs away, and I think he scored six or seven on the day," Brian Mustill, who coached Musiala at Under-8 and Under-10 level recalled (via BBC Sport). "But it was his desire to win the ball having lost it, his energy levels to win the ball back. He chased the whole length of the pitch to win it back and then go and beat the whole team again."
However at 16, he traded Chelsea for Bayern. There is no bad blood, and Musiala frequently speaks highly of his time with the Blues.
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"They (Chelsea and England) are family for me, and I am sure that I remain a member of the family, even though I’m no longer there," the midfielder told the The Athletic. "I wouldn’t be where I am right now without the trust and support of Chelsea and the FA, throughout the hard times and fun times. It wasn’t always easy, but they made me the player I am now."
Chelsea academy products have infamously seen their first-team opportunities limited at Stamford Bridge over the years. Musiala's departure was confirmed on 2 July 2019 - two days before Frank Lampard was appointed as the Blues' new boss.
Lampard would present youngsters with chances that had previously rarely been afforded to those from the Chelsea youth system. However, this was after Musiala's time - he had seen Hudson-Odoi restricted to cameos during the 2018/19 season by Maurizio Sarri - and the clearer path to the Bayern first team has been cited as a further reason for the England youth international moving to Bavaria.
How Musiala's route to the Chelsea first team during the Lampard regime would have panned out is now purely hypothetical, but he made his senior debut for Bayern within 11 months of moving to the club and is a first-team regular at 17. Bavaria held up their end of the first-team opportunities bargain.
It was Hudson-Odoi's older brother, Bradley, who helped seal Musiala's move to the Bundesliga champions.
Bradley Hudson-Odoi is Musiala's agent, and his brother was the subject of heavily reported interest from Bayern during the 2018/19 season. Bayern sporting director Hasan Salihamidzic and Bradley Hudson-Odoi stayed in touch, and this helped to pave the way for Musiala's switch in the summer of 2019.
And then there's Brexit. Musiala was just 13 (THIRTEEN) when Britain voted to leave the EU in 2016, but everybody's favourite dinner party conversation topic was a further contributing factor in his decision to move to Bayern.
The Chelsea youth product was born in Germany to a German mother and British-Nigerian father. Bavarian Football Works report that with Britain poised to leave the EU without a deal in 2019, his family opted to do a spot of leaving themselves.
The Athletic's Raphael Honigstein - who broke the news that Musiala had pledged his international allegiance to Germany - stated that Brexit was 'a factor' in his mother's decision to return to Germany in 2019.
So ironically, Lampard can sort of blame the Tories for the fact that he never got to work with the potential star.