Borussia Dortmund paid around €20 million to sign the 19-year-old from RB Salzburg in the summer, and the France under-19 international, who came through Paris Saint-Germain's academy before spending two seasons in Austria, has quickly become one of the finds of the young season.
Gadou has started six of Dortmund's first seven competitive games, impressing with commanding performances and remarkable pace for a player of 1.95 metres.
Centre-back partner Nico Schlotterbeck has been full of praise for the new arrival, telling club media: "The new signings that came in are all top-class.
"Just thinking about Joane Gadou playing alongside me in central defence, that's just top-class."
Gadou's defending has already reached a high level, but head coach Niko Kovač is working intensively with him on his passing and build-up play, according to the Ruhr Nachrichten.
His defensive quality was on full display against VfB Stuttgart, when he chased down a breaking Ermedin Demirovic at a sprint speed of 36 km/h and slid in with a perfectly timed tackle. Kovač explained after that match where the remaining work lies.
"How he defends the ball, that's outstanding," the coach said. "That's exactly why we signed him. On the ball he needs to solve some situations differently, but we're working on that. When you have young players, you also have to allow them mistakes."
The newspaper reports the specific areas of focus are positioning, control and awareness before receiving the ball. Gadou has established himself as the right-sided centre-back in Dortmund's back three since his move.