Marchment, 23, has skated in 37 games for the Toronto Marlies this season, recording nine goals and 12 assists for 21 points, earning AHL Player of the Week honours for the week ending November 5, 2017. In 2016-17, he split his season between the Marlies and the ECHL's Orlando Solar Bears after signing an AHL contract on April 8, 2016. In 49 career AHL games, he has 22 points (10 goals, 12 assists).

Marchment attended Development Camp with the Maple Leafs in 2016 and 2017 and later took part in Maple Leafs Training Camp in the same years.