In March 2023, Riccardo Calafiori had a chat with Heiko Vogel, his interim manager at Basel, that would change his football career.
"Ricky, do you want to maximise your career?" said Vogel.
He replied: "What do you mean coach?"
"I think you are playing the wrong position."
Vogel recalls that conversation with Sky Sports from Germany, where Calafiori finished starring for Italy at Euro 2024 as a centre-back. But he had barely played in that role until Vogel switched him from a left-back to the heart of the Basel defence just 15 months before the tournament.
"I felt he had a lack of speed as a full-back for reaching the highest level. Playing centre-back, he had more than enough," Vogel says.
"He didn't think about it many seconds: let's work together. I put him from the full-back position into the centre and he did it well."
In fact, it looks like a masterstroke. Calafiori's few months spent as Basel's centre-back earned him a move to Bologna last summer. Head coach Thiago Motta, who guided the Italian club to the Champions League with Calafiori as their key centre-back, did not even consider using him as a full-back.
And it was an outstanding Serie A campaign for the 22-year-old. He topped the Bologna charts for most interceptions and aerial duels won, but his attacking numbers mainly stood out.
No central defender managed more assists in Europe's top five leagues than Calafiori, while his two goals in the 3-3 draw with Juventus towards the end of last season demonstrated his own eye for goal. There is very little he cannot do.
Then Calafiori went on a lung-bursting run across the whole length of the pitch to set up Italy's late equaliser in their 1-1 draw with Croatia to send them through to the Euro 2024 knockout stages. The moment came just a month after his first international call-up and in just his fifth match for Italy. No wonder a big move emerged.
Arsenal have completed a move for the defenderin a deal worth €50m (£42.1m) and you can see why the Italian would be a good fit.
The key attributes of Mikel Arteta's team involve possession, breaking the lines, defensive solidity and set-piece prowess. Calafiori fits the bill.
"I like Arteta's style, everything is about possession. Ricky likes possession," adds Vogel.
"If you want to build up the game and have possession, he's brilliant. If you followed the European Championships, his rushes into the midfield were breaking the opponents' lines.
"He has a very good heading game in defence or the offensive, he was very dangerous in front of goal from set pieces."
The stepping into the midfield is no surprise given who Calafiori's model is. "[John] Stones is my reference," the defender said in a recent interview.
"His style of play is closest to mine. It's not off the cuff when I go into midfield. It's following the guidelines of the coach."
And look at the managers he has worked under. What do his former coaches Jose Mourinho, Vogel and Thiago Motta have in common? A link to Barcelona, La Masia academy or Pep Guardiola, the main source of improvement behind Man City's Stones.
No wonder Guardiola disciple Arteta – along with Chelsea manager Enzo Maresca – were interested in the defender. The experience of different types of coaches means Calafiori is a modern manager's defensive dream.
"Absolutely he is, because he has everything," Vogel adds. "It shows that he's really intelligent.
"His game intelligence is very great, he can adapt to different systems, positions and coaches. He has everything to get to the highest level.
"On one hand you have the possession game and he has everything with that, but also a full-back and a centre-back needs to be a good defender. He's aggressive, good at the defensive duels and one-versus-one situations.
"He is still improving, he's a young guy. He's had Thiago Motta and next season it's Mikel Arteta, it will be good for his career."
We've seen the why, but the question is where he will fit in at Arsenal. It will prove difficult to dislodge Arsenal's first-choice defensive pairing of William Saliba and Gabriel Magalhaes, who have featured together 79 times over the past two campaigns.
Arsenal also had the meanest defence in the Premier League last season, only conceding 29 goals. Yet while Ben White, Gabriel and Saliba were mainstays of the backline, the left-back berth is an area for summer surgery.
None of Oleksandr Zinchenko, Jakub Kiwior and Takehiro Tomiyasu claimed the role consistently last season, while Jurrien Timber, who started the previous campaign in that role, is only just back from a serious knee injury.
So after all the progression to shift to centre-back, is his original position of left-back Calafiori's best bet for an immediate Arsenal spot?
"Of course it's possible," Vogel says when asked if Calafiori could still be a top-quality left-back. "The interpretation of the full-back position, Arteta's idea could be different. Because he's good at technique and good at crosses.
"But if you ask me what his best position is, if you build up with three centre-backs then it's the left one, or if you build up in a four then it's the left centre-back."
So Calafiori may have to wait for his chance – after all, he is not the finished product yet. "In some situations, he needs to be more patient," says Vogel.
"His winning mentality is great but sometimes he's too impatient for the situation. So he risks losing the ball in good situations, but it's a question of experience. And experience is about years. He's getting his years now."
But, in the same way Guardiola has moulded Josko Gvardiol into a defender who can both operate inside the pitch and on the flanks, Arteta may have a similar plan up his sleeve for the Italian who set tongues wagging out in Germany.
When does the summer transfer window open and close?
The 2024 summer transfer window in the Premier League and Scottish Premiership is officially open.
The window will close on August 30 at 11pm UK time in England and at 11.30pm in Scotland.
The Premier League and Scottish Premiership brought forward Deadline Day to link up with the other major leagues in Europe. The closing dates were set following discussions with the leagues in England, Germany, Italy, Spain and France.