The Canadian whiz-kid remained with Vancouver Whitecaps until the following January. It was a big deal for all involved and Bayern had big plans for Davies.
Turning him into the best left-back in European football probably wasn't one of them. But that's the claim being thrown around right now.
The truth is that Davies has excelled further back all season. But the COVID-19 crisis has shone the spotlight on the Bundesliga as the only game in town. Never more so than in midweek, when Davies put in a virtuoso display in the win over title rivals Borussia Dortmund.
“Alphonso is a player with a lot of heart and a lot of power, extreme power,” Thomas Müller said afterwards. “Sometimes maybe he does not have the best position on the field, but he gets the opponent feeling ‘I have time, I have time', but then: ‘meep meep, meep meep!' The Bayern roadrunner comes ahead and steals the ball.”
For Bayern coach Hansi Flick, none of this comes as a huge surprise. Davies was signed as a winger, sure, but always had the qualities to play further back.
“I’ve always been confident Davies can fulfil the role of left-back,” Flick said during the Bundesliga's winter break. “He’s our get-out-of-jail-free card with his pace and strength to recover his position, and he’s a great passer of the ball.
“It’s about performances, but we’re certainly well equipped at left-back with him and David [Alaba].”
When he officially completed his move to Bavaria, Davies had Arjen Robben, Franck Ribéry, Kingsley Coman and Serge Gnabry for competition. He had to be patient, making six substitute outings during his first season in the Bundesliga. The longest of those was 31 minutes in the 6-1 drubbing of Mainz – a game in which he became Bayern's first scorer born in the 2000s.
The significance of that game is he came on in place of Austrian left-back David Alaba. What has sped up his conversion from winger to wing-back is injuries to Niklas Süle and Lucas Hernández. With the pair ruled out for most of the season, Alaba has been forced inside to partner Jérôme Boateng or Benjamin Pavard at centre-back.
But Davies has made the most of his chance – and that's putting it mildly. The Edmonton native has racked up five assists and two goals while playing as a full-back. That's on top of the 5.41 take-ons he attempts (per 90), completing 3.48.
No left-back in the Bundesliga who's played in at least 20 per cent of available minutes can better either figure. In fact, no-one deployed on the right gets anywhere near either. Even Dortmund's Moroccan sensation Achraf Hakimi trails with 2.53 completions from 4.24 attempts.
It's easy to laud Davies' attacking ability. The 19-year-old is a whirlwind when he attacks and against Dortmund alone he completed five of the seven take-ons he attempted – often in advanced areas.
There are, though, still nuances to playing at full-back which he must learn if this is to become his full-time position. Something he's all too aware of.
“Obviously being a young player I get caught out of position a lot and I'm happy to have the speed I have,” said Davies. “That's a factor in my game that I use very well, but I think over the years going forward with this team I will definitely learn more about my position, better positioning so it doesn't look like I'm out of position just running back as fast as I can to catch up.”
That's not to suggest Davies is a defensive liability. Far from it, in fact. He has won 8.7 defensive duels (per 90) this season. That's more than any other wing-back or full-back in Germany's top-flight and the 11th-most compared to all players.
Davies' recovery pace was used to full effect in Tuesday's potentially title-clinching win over Dortmund, when he made up 20 yards on Erling Håland to halt the Norwegian's dangerous progress into the Bayern penalty area.
Given his natural attacking prowess, it's inevitable Davies will get caught up the field in advanced positions. Preventing teams exploiting that is a challenge for coach Flick to iron out.
Another area of his game which needs work is his decision-making in possession. Davies loses possession 17.74 times per 90 – either by running into a dead-end or making a poor pass. That is a figure which needs to come down.
However, Davies has all the tools to become one of the modern-day greats. Luckily for Bayern's road runner there's plenty of road ahead.