The Capitals selected Alexeyev with their first-round pick, 31st overall, in the 2018 NHL Draft.
Alexeyev, 20, finished his first AHL season with 21 points (3g, 18a) in 58 games with the Hershey Bears. Alexeyev ranked third among Hershey defensemen and 12th among all AHL rookie defensemen in points. Additionally, his 18 points at even strength tied for sixth among all AHL rookie defensemen. The St. Petersburg, Russia, native led Hershey defensemen in games played and ranked third in plus/minus (8).
In the 2018-19 season, the 6'4", 210-pound defenseman recorded 43 points (10g, 33a) in 49 games with the Red Deer Rebels in the Western Hockey League (WHL), ranking eighth among defensemen in points per game (0.88). In 135 career games with Red Deer, Alexeyev recorded 101 points (21g, 80a).
Alexeyev has represented Russia at the 2019 World Junior Championship, the 2016 Under-18 World Championship and the 2016 Ivan Hlinka Memorial. Alexeyev recorded six points (2g, 4a) in seven games en route to winning the bronze medal at the 2019 World Junior Championship.
