Bahnsen's baseball career started with Rookie of the Year honors. For the rest of his 16 year stay in the Majors he would be a serviceable but not great pitcher. He was in the starting rotation for the Yankees, White Sox, A's and Expos until 1977. Montreal moved him to the bullpen in 1978. He was released by the Expos prior to the start of the 1982 season. The Angels picked him up only to release him a month later. The Phillies then signed him to a minor league contract. Bahnsen would play in the Phillies system until 1983 but his final Major League game would be October 2, 1982. He pitched an inning and a third striking out 3, the Mets' George Foster, Dave Kingman and Brian Giles.