Career
He played for the California Angels (1971, 1973–1976 and 1980–1983), Kansas City Royals (1976–1978), Boston Red Sox (1978–1979), New York Mets (1979), Pittsburgh Pirates (1980) and Saint Louis Cardinals (1984–1985). Hassler was drafted in the 25th round of the 1969 amateur draft by the California Angels and made his Major League debut on May 30, 1971, pitching four innings in a 7–4 loss to the Yankees. He lost 17 straight games (as a starter and in relief) between 1975–1976.
Hassler"s final Major League appearance was on May 7, 1985, against the San Diego Padres.
Though he played for six teams (including two separate stints with the Angels) during his Major League career, Hassler was never involved in a trade. His contract was purchased several times and he signed as a free agent twice.
He currently resides in Phoenix, Arizona.