Harnisch suffered from a lack of run support upon his arrival in Houston. Despite leading the National League (NL) with a 2.22 ERA, his record stood at 5–7 leading into the 1991 MLB All-Star Game. NL manager Lou Piniella added Harnisch to his squad regardless of his losing record, and Harnisch pitched a scoreless sixth inning in the NL's 4–2 loss.