Heise played an important bench role for the 1975 American League Championship Series winning Red Sox. In the first two weeks of July, while Rico Petrocelli was sidelined by an eye injury, Heise batted .344 with seven runs and seven RBIs. He played all eighteen innings of a July 6 doubleheader with the Cleveland Indians. In the first game, he drove in three of the five Bosox's runs to carry his team to a 5-3 victory. In the second game, he went 3-for-4 with two runs scored and two RBI in his team's 11-10 loss. For the season, he batted .214 with 21 RBI. Though he was on the Red Sox post season roster, he did not appear in any post season games.