[6] After his college career, McMann signed a two-year contract with the Toronto Marlies of the American Hockey League (AHL).
[8] In reward for his play, the Toronto Maple Leafs, the Marlies' parent club and NHL affiliate, signed McMann to a two-year, entry-level contract worth slightly over league minimum.
After recording six points in three games to be named the AHL's Player of the Week for January 8, 2023 (for a collective season total of 15 points in 17 games played), McMann was recalled by the Maple Leafs on January 10, after placing defenceman T.J. Brodie on injury reserve.
[11] After eight games with the Maple Leafs, McMann was returned to the Marlies; he recorded one disallowed goal in his NHL stint in a depth role with the team's fourth line.
[12][13] McMann missed part of the Maple Leafs' 2023–24 training camp due to a lingering lower-body injury he sustained the previous season.