MacArthur, 6-foot-1, 197 pounds, currently plays for Acadie-Bathurst of the Quebec Major Junior Hockey League and has posted 25 goals and 43 points in 26 games this season. He ranks second on the Titan for goals and fourth for scoring. He's currently tied for fifth in the QMJHL for goals.
The 21-year-old left wing has played three seasons in the QMJHL, all with Acadie-Bathurst, tallying 61 goals and 95 points. In nine games for the Titan in the 2021 playoffs, MacArthur recorded six goals and 11 points.
MacArthur's Lightning contract begins with the 2022-23 season. MacArthur will continue to play for Acadie-Bathurst for the remainder of the season.