McMann's impact on the Seattle Kraken after he arrived in a trade with the Toronto Maple Leafs on March 6, 2026, earned him a six-year, $34.5 million contract (average annual value of $5.75 million) that he signed with Seattle on June 21 in lieu of becoming an unrestricted free agent.

At age 30, McMann set NHL career highs in goals (29), assists (17) and points (46) in 78 games, with 14 points (10 goals, four assists) in 18 games after the Kraken acquired him before the NHL Trade Deadline. The deal reunited McMann with Seattle coach Lane Lambert, who was an assistant with the Maple Leafs the previous season, and his 29 total goals were the most of any player on the Kraken roster.

The former standout at Colgate University played three seasons in the ECHL and American Hockey League before getting an opportunity with the Maple Leafs, signing as free agent April 29, 2022, and a two-year, $2.7 million contract ($1.35 AAV) on March 13, 2024. Exactly one month earlier, McMann had his first NHL hat trick in Toronto's 4-1 win against the St. Louis Blues at Scotiabank Arena.

McMann had a team-high 20 points (10 goals, 10 assists) in 34 games as a senior captain before the 2020 ECAC tournament was cancelled because of the COVID-19 pandemic. He was a nominee for the Hobey Baker Award given to the top player in NCAA men's hockey and voted winner of the Terry Slater Award for his lasting impact on the Colgate program. He left with 92 points (37 goals, 55 assists) in 145 NCAA games.

Prior to attending Colgate, McMann played three seasons for Bonnyville in the Alberta Junior Hockey League, was named the 2016 AJHL Most Valuable Player and graduated Wainwright High School with the Class of 2014.