Grundstrom, 19, skated in 45 regular season games with Frolunda of the Swedish Hockey League (SHL), collecting 14 goals and six assists for 20 points. The Umea, Sweden native led all U20 SHL skaters in goals (14) and points (20) this season. Grundstrom also appeared in seven games with Team Sweden at the 2017 IIHF World Junior Hockey Championships, where he registered seven points (three goals, four assists) placing him 11th in tournament scoring.
He was originally drafted by the Maple Leafs in the second round (57th overall) at the 2016 NHL Draft.