The 5'10", 192-pound forward made his AHL debut with Abbotsford in 2021.22 and has since appeared in 105 regular season games with the club, registering 52 points (21-31-52), 77 penalty minutes, and a +10 rating. Previously, Nielsen played five full WHL seasons split between the Vancouver Giants and Calgary Hitmen, amassing 175 points (82-93-175) in 241 games.