Youssoufa Moukoko has revealed how he hit it off almost immediately with American Gio Reyna at Borussia Dortmund, despite the language barrier between the teenaged pair.
Reyna followed Moukoko to the Ruhr district in summer 2019, having been born in England and raised in the USA.
Moukoko spoke German; Reyna didn't - so the duo had to let their football do all the talking in their short time together in the BVB U19s.
"We never talked because he did not speak German and I had my difficulties with English," Moukoko said of his relationship with Reyna. "But on the pitch, we understood each other. The chemistry was unbelievable."
Watch: Gio Reyna, Youssoufa Moukoko and Dortmund's next generation
Striker Moukoko and attacking midfielder Reyna played together in 16 matches at U19 level during the first half of the 2019/20 season. Moukoko registered 21 goals and nine assists in that time, while Reyna had a direct hand in 11 goals before being promoted to the first team during the winter break.
Reyna duly made his senior debut at 17 in January 2020, and went on to open his account in the DFB Cup and make history as the youngest US national to appear and assist a goal in the UEFA Champions League.
The freshly minted USA international, now 18, has since become a regular in Lucien Favre's side, where he was reunited with Moukoko in the 5-2 win at Hertha Berlin on Matchday 8 of the current campaign, thanks to a DFL rule change on the minimum age requirement of players in the Bundesliga.
With the threshold lowered from 16 and a half to 16, Moukoko made history as the youngest player in Bundesliga history when he replaced Erling Haaland in the 86th minute at Hertha's Olympic Stadium - just one day after his 16th birthday. A year earlier, he had received a personalised present from Lionel Messi.
"I can't do anything about being good at football," Moukoko told DAZN prior to his milestone outing, having scored over 150 goals for Dortmund's U17s and 19s.
"It was always my dream to become a professional football player. And if you have that dream you have to chase it like a lion. The one who works harder gets rewarded in the end."
Moukoko's next honour could be a slice of Champions League history.
Should the teenaged goal fiend feature for Dortmund against Club Brugge in Group F on Tuesday, he will become the tournament's youngest debutant.
Celestine Babayaro holds the current record, having started for Anderlecht against Steaua Bucharest in the 1994/95 group stage, aged 16 years and 87 days.