Heep was an extra lefthanded bat when the Astros sent him to the Mets for pitcher Mike Scott in December 1982. His four pinch-hit home runs in 1983 led the majors and set a Mets record. Heep was the top pinch hitter (9-for-30) for the 1986 World Champion Mets. He had career highs of 320 at-bats, 49 RBI, and a .300 batting average in 1989 for the Red Sox when they lost several outfielders to injury.