[1] In 2014, he headed over the Atlantic to hone his skills in the Western Hockey League (WHL), joining the Moose Jaw Warriors.

[9] As an undrafted free agent, Smejkal signed a one-year, entry-level contract with the Ottawa Senators of the National Hockey League (NHL) on 4 May 2023.

[10] The signing came in response to the Senators' stated goal of bolstering its scoring and organizational depth ahead of a 2023–24 season in which they hoped to make the Stanley Cup playoffs for the first time since 2017.

[11] Smejkal was assigned to Ottawa's American Hockey League (AHL) affiliate, the Belleville Senators, to start the 2023–24 season.

[14] On 22 December, Smejkal collected his first NHL point, assisting on Jacob Bernard-Docker's goal in a 6–4 loss to the Colorado Avalanche.

In the final game of the season on 16 April, Smejkal recorded his first NHL goal against Linus Ullmark in 3–1 win over the Boston Bruins.