Youssoufa Moukoko

Moukoko debuted for the Germany under-16 side on 11 September 2017 in a 3–1 win over Austria and scored both goals against the same opponent two days later, the youngest player to have represented the team. In October, Dortmund and the DFB agreed not to select him further for the time being in order to limit the attention on him. He was called up to the under-19s in February 2020, though the fixtures fell to the pandemic, and debuted for the under-20s that September at fifteen. Named in the under-21 squad for the 2021 UEFA European Under-21 Championship as the youngest player selected, he was injured in training and did not play as Germany won the tournament. His debut came on 2 September 2021 against San Marino, with two goals, making him the youngest to play for and score for the side. On the strength of his autumn form for Dortmund and three goals in three under-21 matches during 2022, Hansi Flick named him in Germany's World Cup squad. He and Füllkrug were the only uncapped players in it. He debuted on 16 November in a 1–0 friendly win over Oman, at 17 years and 361 days Germany's fourth-youngest senior international behind Willy Baumgärtner, Marius Hiller and Uwe Seeler. He came on in stoppage time of the opening defeat to Japan and did not feature again, Flick preferring Füllkrug, Thomas Müller and Kai Havertz as Germany went out in the group stage. He was in the squad for the 2023 UEFA European Under-21 Championship, where he missed a penalty in a 1–1 draw with Israel…

Youth

Moukoko joined the under-13 side of FC St. Pauli in October 2014. The outdoor season had finished, so his first months were spent in indoor tournaments, where he was repeatedly top scorer. He was moved up to the under-15 side at eleven and scored 23 goals in 13 matches. Borussia Dortmund signed him for their academy in July 2016. He scored 33 in 21 for the under-15s in his first season, then entered the Under 17 Bundesliga West in 2017–18 as the division's only thirteen-year-old, finishing as its top scorer with 40 goals in 28 games and scoring the winner in the national under-17 final against Bayern Munich. He was top scorer again the following season with 46 in 25, passing Donis Avdijaj's divisional record of 44. Promotion to the under-19s at fourteen changed nothing. He scored six on his debut in a 9–2 win over Wuppertaler SV, passed Haluk Türkeri's fifteen-year-old league record of 33 goals by the twentieth matchday, and finished a season curtailed by the COVID-19 pandemic with 34 in 20, twenty-one clear of the next-highest scorer in the division. He became the youngest player to appear in the UEFA Youth League against Barcelona in September 2019 and its youngest scorer against Inter Milan five weeks later. By the autumn of 2020 kicker judged him "almost grotesquely under-challenged" in youth football, noting that he had scored ten goals in three under-19 league appearances and three more in a cup tie.

Borussia Dortmund

Record debut…

A left-footed striker of modest build, Moukoko is a penalty-area finisher rather than a focal point. His shot volume and conversion have been consistently high at every level, and the Opta figures from his first Copenhagen season placed him second in the division for both goals and expected goals per 90 minutes. His youth record rested less on physical advantage than on movement and finishing, since he was habitually the smallest and youngest player on the pitch. The recurring reason given for leaving him out has been the same at three clubs. Svensson explained a run of omissions by saying he wanted a big striker on the last line as a threat from crosses, which was not Moukoko's strength. Haise at Nice made a comparable judgement in favour of the more physically imposing Guessand. Otto Addo, then Dortmund's talent manager, praised his willingness to put in additional individual training sessions and to seek out coaching staff himself, and Mike Tullberg made him under-19 captain, describing him as a model in many respects.

Moukoko spent his first ten years in the Briqueterie quarter of Yaoundé, the Cameroonian capital. He has said he played no organised football there, only in the street, and that he decided at four to become a footballer after watching the 2009 Champions League semi-final between Chelsea and Barcelona on television. Joseph Moukoko, born 1951, a Cameroonian who had lived in Hamburg as a German citizen since the 1990s, brought him to Germany in the summer of 2014. The nature of that relationship became the central question in the later dispute over his age.