The Toronto Maple Leafs waited patiently for Gauthier to live up to the promise that persuaded him to select the 6-foot-5 forward in the first round (No. 21) of the 2013 NHL Draft.

The Maple Leafs chose Gauthier after he scored 22 goals in 60 games during his first season with Rimouski of the Quebec Major Junior Hockey League in 2012-13. He had intended to play NCAA hockey at Harvard, but a phone call from Sidney Crosby, a junior star with Rimouski, persuaded him to change his mind.

Gauthier returned to Rimouski for two more seasons before turning pro in 2015-16. He spent most of the season with Toronto of the American Hockey League, but did get a seven-game call-up with the Maple Leafs late in the season. He made his NHL debut against the Buffalo Sabres on March 19, 2016, and got his first point, an assist, against the Columbus Blue Jackets on April 6.

He began the 2016-17 season in the AHL but was recalled in mid-December and scored his first NHL goal against the Colorado Avalanche on Dec. 22, 2016. He finished with two goals and an assist in 21 games for the Maple Leafs before being returned to the minors, where a hamstring injury ended his season.

Gauthier spent most of the 2017-18 season in the AHL, scoring one goal in nine games with the Maple Leafs, before making the NHL for good as a bottom-six forward in 2018-19, finishing with 14 points (three goals, 11 assists) in 70 games and going scoreless in seven Stanley Cup Playoff games. He showed more of his offensive game in 2019-20, scoring seven goals in 61 games.

NOTES & TRANSACTIONS

• QMJHL All-Rookie Team (2013)
• Signed as a free agent by Arizona, January 11, 2021.
• Signed as a free agent by New Jersey, October 8, 2021.