The Capitals selected Riat with their fourth-round pick, 117th overall, in the 2016 NHL Draft.
Riat, 23, has recorded 22 points (11g, 11a) in 36 games with EHC Biel-Bienne in the National League in Switzerland this season. The 6'0", 180-pound forward leads EHC Biel-Bienne in penalty minutes (57) and ranks fifth on the team in goals. In 223 career games in the National League, Riat has recorded 106 points (50g, 56a).
Prior to the National League, the Geneva, Switzerland, native played two seasons in the Saskatchewan Midget AAA Hockey League, winning the league championship with Notre Dame in 2013-14. Riat played 40 games with Malmö's U-20 affiliate in Sweden's SuperElit in the 2014-15 season, registering 14 points (7g, 7a) and made his debut in Sweden's professional Allsvenskan league as a 17 year old that same season.
Riat earned a silver medal with Switzerland at the 2018 IIHF World Championship, posting a +1 plus/minus rating in six games played. Riat also represented Switzerland at the 2016 and 2017 World Junior Championships, recording a combined 10 points (3g, 7a) in 11 games in the two tournaments.