|- style="background:#fbb" | 149 || September 15 || Expos || 3–4 || Bill Gullickson (11–7) || Jerry Koosman (14–13) || Bob James (9) || 20,831 || 79–70 |- style="background:#fbb" | 150 || September 16 || Expos || 4–8 || Jeff Reardon (6–7) || Renie Martin (1–3) || Bob James (10) || 26,273 || 79–71 |- style="background:#bfb" | 151 || September 17 || Mets || 2–1 || Shane Rawley (12–7) || Dwight Gooden (16–9) || None || 20,483 || 80–71 |- style="background:#fbb" | 152 || September 18 || Mets || 5–8 || Tom Gorman (5–0) || Larry Andersen (3–4) || Jesse Orosco (30) || 18,765 || 80–72 |- style="background:#bfb" | 153 || September 19 || Mets || 13–5 || Steve Carlton (13–7) || Ron Darling (12–8) || None || 19,142 || 81–72 |- style="background:#fbb" | 154 || September 21 || @ Pirates || 1–5 || Rod Scurry (5–6) || Jerry Koosman (14–14) || None || 4,940 || 81–73 |- style="background:#fbb" | 155 || September 22 || @ Pirates || 1–2 (12) || Don Robinson (5–6) || Larry Andersen (3–5) || None || 6,927 || 81–74 |- style="background:#fbb" | 156 || September 23 || @ Pirates || 2–4 || John Tudor (11–11) || Shane Rawley (12–8) || John Candelaria (2) || 11,249 || 81–75 |- style="background:#fbb" | 157 || September 24 || @ Mets || 5–7 || Jesse Orosco (10–6) || Larry Andersen (3–6) || Brent Gaff (1) || 11,071 || 81–76 |- style="background:#fbb" | 158 || September 25 || @ Mets || 4–6 || Ed Lynch (9–8) || Larry Andersen (3–7) || None || 13,812 || 81–77 |- style="background:#fbb" | 159 || September 26 || @ Mets || 1–7 || Sid Fernandez (6–6) || Jerry Koosman (14–15) || None || 5,251 || 81–78 |- style="background:#bbb" | – || September 28 || Pirates || colspan=6 | Postponed (rain); Makeup: September 30 as a traditional double-header |- style="background:#fbb" | 160 || September 29 || Pirates || 0–4 || Rick Rhoden (14–9) || Charles Hudson (9–11) || None || 27,493 || 81–79 |- style="background:#fbb" | 161 || September 30 (1) || Pirates || 0–2 || John Tudor (12–11) || John Denny (7–7) || Don Robinson (10) || see 2nd game || 81–80 |- style="background:#fbb" | 162 || September 30 (2) || Pirates || 2–7 || Larry McWilliams (12–11) || Shane Rawley (12–9) || None || 17,292 || 81–81 |- Roster Player stats Batting Starters