Wallmark was selected by the Carolina Hurricanes in the fourth round (No. 97) of the 2014 NHL Draft after getting 10 points (three goals, seven assists) in 41 games for Lulea HF of the Swedish Hockey League.

Wallmark played two more seasons in the SHL before coming to North America for 2016-17, where he was assigned to Charlotte of the American Hockey League.

In Charlotte, Wallmark had 46 points (24 goals, 22 assists) in 67 games to earn a late-season call-up. He made his NHL debut against the New York Islanders on March 13, 2017, and got his first NHL point, an assist, one day later, also against the Islanders.

Wallmark returned to Charlotte for the start of the 2017-18 season, where he again played well with 55 points (17 goals, 38 assists) in 45 games. As a result, he was recalled by Carolina and scored his first NHL goal in his season debut against the St. Louis Blues on Dec. 30, 2017. It was his only point in 11 games.

Wallmark stuck with Carolina in 2018-19, getting 28 points (10 goals, 18 assists) in 81 games while playing in a bottom-six role to help the Hurricanes advance to the Stanley Cup Playoffs for the first time since 2009. In the playoffs, Wallmark had five points (one goal, four assists) in 15 games as the Hurricanes advanced to the Eastern Conference Final before being swept by the Boston Bruins.

The following season, Wallmark had 23 points (11 goals, 12 assists) in 60 games before he was traded to the Florida Panthers on Feb. 24, 2020.

NOTES & TRANSACTIONS

• Traded to Florida by Carolina with Erik Haula, Eetu Luostarinen and Chase Priskie for Vincent Trocheck, February 24, 2020.
• Signed as a free agent by Chicago, October 12, 2020.
• Traded to Florida by Chicago with Lucas Carlsson for Brett Connolly, Henrik Borgstrom, Riley Stillman and a 7th-round pick in 2021 NHL Draft, April 8, 2021.