|| September 7 || @ Mets || 3–9 || Nolan Ryan (5–1) || Bill Champion (5–8) || None || 28,937 || 55–82 |- style="background:#fbb" | 138 || September 8 || Cardinals || 3–4 || Chuck Taylor (7–2) || Woodie Fryman (11–12) || Mudcat Grant (4) || 2,025 || 55–83 |- style="background:#fbb" | 139 || September 9 || Cardinals || 2–6 || Nelson Briles (15–12) || Grant Jackson (12–15) || Mudcat Grant (5) || 2,547 || 55–84 |- style="background:#bfb" | 140 || September 10 || Cubs || 6–2 || Rick Wise (13–11) || Ken Holtzman (16–10) || None || 4,164 || 56–84 |- style="background:#bfb" | 141 || September 11 || Cubs || 4–3 || Jeff James (1–0) || Dick Selma (12–7) || Grant Jackson (1) || 4,255 || 57–84 |- style="background:#fbb" | 142 || September 12 || Expos || 0–4 || Bill Stoneman (10–17) || Bill Champion (5–9) || None || 2,739 || 57–85 |- style="background:#fbb" | 143 || September 13 || Expos || 5–7 || Dan McGinn (6–10) || Woodie Fryman (11–13) || Jerry Robertson (1) || 3,154 || 57–86 |- style="background:#fbb" | 144 || September 14 || Expos || 2–7 || Steve Renko (5–6) || Grant Jackson (12–16) || Claude Raymond (2) || 3,327 || 57–87 |- style="background:#bfb" | 145 || September 15 (1) || Pirates || 2–1 || Rick Wise (14–11) || Bob Veale (12–12) || None || see 2nd game || 58–87 |- style="background:#bfb" | 146 || September 15 (2) || Pirates || 4–3 || Jeff James (2–0) || Bo Belinsky (0–3) || None || 2,933 || 59–87 |- style="background:#fbb" | 147 || September 16 || Pirates || 5–9 || Bob Moose (11–3) || Woodie Fryman (11–14) || Joe Gibbon (10) || 1,169 || 59–88 |- style="background:#fbb" | 148 || September 17 || @ Cubs || 7–9 || Ferguson Jenkins (20–14) || Bill Champion (5–10) || Rich Nye (3) || 6,062 || 59–89 |- style="background:#bfb" | 149 || September 18 || @ Cubs || 5–3 || Grant Jackson (13–16) || Phil Regan (12–6) || None || 5,796 || 60–89 |- style="background:#fbb" | 150 || September 19 (1) || @ Expos || 6–10 || Gary Waslewski (3–9) || Rick Wise (14–12) || Howie Reed (1) || see 2nd game || 60–90 |- style="background:#fbb" | 151 || September 19 (2) || @ Expos || 1–3 || Steve Renko (6–6) || Jeff James (2–1) || None || 17,083 || 60–91