Stützle was selected as the best player on Team Germany at the end of the first qualifying match against Kazakhstan in the 2020 World Junior Championships. He had five assists during the tournament, and averaged 18 minutes ice time in five games, and was an A-rated skater. In the 2021 World Junior Ice Hockey Championships, Stützle was named team captain for Germany and lead them to the playoff round for the first time in World Juniors history. He tallied five goals and five assists in five games and was named player of the game for the team's second game against Canada. After the tournament ended, Stützle was named best forward by the directorate and one of the members of the media all-star team.