The Capitals selected Leason with their second round pick, 56th-overall, in the 2019 NHL Draft.
Leason, 20, was ranked fifth among right wings and 21st overall among North American forwards by NHL Central Scouting. The 6'4", 210-pound right wing registered 89 points (36g, 53a) in 55 games with the Prince Albert Raiders of the Western Hockey League (WHL) last season. Leason led Prince Albert in points and ranked eighth in the WHL in the 2018-19 season. The Calgary, Alberta, native recorded 25 points (10g, 15a) in 22 playoff games, ranking second in the WHL in playoff points, en route to Prince Albert's Ed Chynoweth Cup as the WHL champions. Leason was named to the WHL (East) First All-Star Team last season.
In 190 career WHL games between Prince Albert and the Tri-City Americans, Leason has recorded 140 points (60g, 80a). He received the 2019 E.J. McGuire Award of Excellence this year, presented annually by the NHL to a prospect who best exemplifies commitment to excellence through strength of character, competitiveness and athleticism.
Leason represented Team Canada in the 2019 World Junior Championship, recording five points (3g, 2a) in five games.