 While playing for the university's Boston Terriers team, he had four goals and 14 points in 19 games as a freshman before making the U.S. under-20 national team for the 2018 World Junior Championships.Nearing the end of the season, Tkachuk was selected for the Hockey East Rookie Team after ranking fifth on the team in points.Leading up to the 2018 NHL Entry Draft, Tkachuk was ranked second overall for North American skaters by the NHL Central Scouting Bureau.