Answer
The answer is 1. FC Gelsenkirchen-Schalke. Leon Goretzka, the talented German midfielder, spent his early footballing years honing his skills at 1. FC Gelsenkirchen-Schalke, a renowned youth team known for developing some of the nation's best young talents. Starting from his early teens, Goretzka showcased his impressive skills and footballing intelligence, laying the foundation for his successful professional career and eventually becoming a regular in the German national team.