 He began his career in the National Hockey League in 1984 when he was signed as a free agent by the New York Islanders.After several seasons with the Islanders, Bassen was traded early in the 1988–89 NHL season to the Chicago Blackhawks.He remained in the Blackhawks organization for two seasons before he was claimed by the St. Louis Blues in the waiver draft prior to the start of the 1990–91 NHL season.