[4] He made his professional debut at the age of 17 in the Champions Hockey League opening round on 30 August 2019 against the Vienna Capitals.

[7] On 13 October, while continuing to train in Germany with Mannheim in preparation for the upcoming 2020–21 season, Stützle suffered a broken hand, requiring surgery with a 6–8 week recovery period.

[5] He scored his first NHL goal on 16 January 2021 against goaltender Jack Campbell in a 3–2 loss to the Toronto Maple Leafs.

[12] Stützle fought Edmonton Oilers defenceman William Lagesson in his first NHL fight on 31 January 2022; and later scored the game's game-winning goal in overtime.

[16] By season's end, Stützle set career highs in goals (39), assists (51) and points (90),[17] while establishing himself as one of the young stars of the game.

[18] 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.