Reinbacher played as a youth in Switzerland with EHC Rheintal and EHC Bülach, before moving to EHC Kloten at the under-15 level. Appearing within Kloten junior ranks, he made his professional debut with the club in the Swiss League (SL), the second tier of the Swiss league system, midway through the 2021–22 season. Reinbacher managed one goal and 10 assists in 27 regular season appearances.[3] He then played in 14 playoff games, which culminated in Kloten securing promotion to the National League (NL), Switzerland's top league.[4][3]
In the 2022–23 season, Reinbacher established himself a regular on Kloten's blueline, attracting attention for doing so as an 18-year-old player, and seeing his average ice time rise from six minutes per game to over 20. He recorded three goals and 19 assists in 46 games during the regular season, and two further points in three playoff games.[4] He received the league's award for the best young player of the year.[5]
Reinbacher had a low profile among evaluators prior to the 2023 NHL entry draft, with some European evaluators identifying him as a potential second-round selection.[6] By November 2022, he was receiving attention from major North American publications, with The Hockey News naming him to their "All-Sleeper Squad" of players who should be considered for the first round.[7] By the time of the draft in June, Reinbacher was mooted as a top ten selection by many, and generally considered likely to be the first defenceman taken in the draft.[8][9][10][11] At the draft, Reinbacher was selected fifth overall by the Montreal Canadiens, with the team's general manager Kent Hughes describing him as "a diamond in the rough with a lot of potential."[1] This made him the highest-drafted Austrian skater in NHL history, alongside Thomas Vanek, who was also drafted fifth overall 20 years earlier.[4] The Canadiens' decision was controversial due to their passing over Matvei Michkov, considered by many to be the most talented player still available at the time, who was subsequently taken by the Philadelphia Flyers. Criticism on social media attracted sports media coverage, notably due to reported abusive messages directed at Reinbacher himself.[12][13][14][15]
On 5 July 2023, the Canadiens signed Reinbacher to a three-year, entry-level contract.[16][17] After what was generally considered a positive appearance at the Canadiens' training camp in the autumn of 2023, he was sent back to Switzerland's National League (NL) for the 2023–24 season.[18][19] Kloten went on to have an "atrocious" season, avoiding the relegation playoffs only because no eligible Swiss league team sought promotion. In the midst of these difficulties, Reinbacher had one goal and ten assists in 35 appearances, having missed some time due to injury.[20] Following the end of the NL season, he was assigned to the Laval Rocket, the Canadiens' American Hockey League (AHL) affiliate, on 18 March 2024.[21] He made his AHL debut on 22 March 2024 in a 3–2 overtime win versus the Belleville Senators recording a goal.[22] In eleven games with Laval, he managed two goals and three assists.[23]
While competing with the Canadiens in exhibition play against the Toronto Maple Leafs on 28 September 2024, Reinbacher exited the game after a hit by Leafs defenceman Marshall Rifai. Days later, it was announced that he had underwent knee surgery, and would miss five to six months of the 2024–25 season.[23]
