Thommy Abrahammson began his career as a hockey player in the youth department of the lower class Godtemplarnas IF, in which he was active from 1961 to 1964. Then the defender ran from 1964 to 1974 for a total of ten years for Leksands IF in Division 1, the top Swedish division and predecessor league of the Elitserien , founded in 1975 . With his team he became Swedish champions in 1969 and 1973 . In the 1972/73 season he also received the goldpuck as player of the year. Following his time in Leksand, the national player and Olympian received a contract with the New England Whalers from the World Hockey Association , for which he was active from 1974 to 1977.
From 1977 to 1980 Abrahamsson played for his ex-club Leksands IF in the Elitserien. He was then re-engaged by his former team from Hartford, which had been accepted into the National Hockey League in 1979 after the dissolution of the WHA and had changed its name to Hartford Whalers on the occasion. For the Whalers, the Swede scored six goals in 32 games in the 1980/81 season and provided eleven templates. He was also in two games for their farm team , the Binghamton Whalers , in the American Hockey League on the ice. From 1981 to 1983 he let his career end in his home country at Timrå IK , with whom he had to accept relegation to Division 1, which is now second class, in the 1981/82 season.