| 1973-04-06 | vs SLN | 1 | W 7-5 | 1-0 | 3 | 51,695 | Steve Blass | Bob Gibson | Jim Rooker | Diego Segui | Ramon Hernandez | 7 | 5 | 2 |
| 1973-04-08 | vs SLN | 2 | W 4-3 | 3-0 | 2 | 0 | Nelson Briles | Rick Wise | Dave Giusti | Wayne Granger | | 11 | 8 | 3 |
| 1973-04-08 | vs SLN | 3 | W 5-3 | 3-0 | 2 | 23,391 | Dock Ellis | Scipio Spinks | Dock Ellis | Scipio Spinks | Ramon Hernandez | 16 | 11 | 5 |
| 1973-04-12 | vs CHN | 4 | W 6-0 | 4-0 | 2 | 3,764 | Bob Moose | Fergie Jenkins | Bob Moose | Fergie Jenkins | | 22 | 11 | 11 |
| 1973-04-14 | @ MON | 5 | L 4-6 | 4-1 | 1 | 21,198 | Nelson Briles | Ernie McAnally | Tom Walker | Nelson Briles | | 26 | 17 | 9 |
| 1973-04-15 | @ MON | 6 | W 8-3 | 5-1 | 1 | 12,101 | Dock Ellis | Mike Torrez | Dock Ellis | Mike Torrez | Dave Giusti | 34 | 20 | 14 |
| 1973-04-17 | @ SLN | 7 | W 4-3 | 6-1 | 1 | 9,851 | Steve Blass | Bob Gibson | Ramon Hernandez | Alan Foster | Jim Rooker | 38 | 23 | 15 |
| 1973-04-18 | @ SLN | 8 | W 8-2 | 7-1 | 1 | 6,228 | Bob Moose | Rick Wise | Bob Moose | Rick Wise | Luke Walker | 46 | 25 | 21 |
| 1973-04-21 | @ CHN | 9 | L 9-10 | 7-2 | 1 | 16,637 | Nelson Briles | Fergie Jenkins | Bob Locker | Nelson Briles | | 55 | 35 | 20 |
| 1973-04-22 | @ CHN | 10 | W 10-4 | 8-3 | 1 | 0 | Dock Ellis | Milt Pappas | Dock Ellis | Milt Pappas | Jim Rooker | 65 | 39 | 26 |
| 1973-04-22 | @ CHN | 11 | L 3-11 | 8-3 | 1 | 28,271 | Steve Blass | Larry Gura | Larry Gura | Steve Blass | Bill Bonham | 68 | 50 | 18 |
| 1973-04-24 | vs SDN | 12 | L 5-7 | 8-4 | 1 | 10,108 | Bob Moose | Steve Arlin | Rich Troedson | Bob Moose | Vicente Romo | 73 | 57 | 16 |
| 1973-04-28 | vs LAN | 13 | L 2-3 | 8-5 | 1 | 9,643 | Nelson Briles | Don Sutton | Don Sutton | Nelson Briles | | 75 | 60 | 15 |
| 1973-04-29 | vs LAN | 14 | L 8-9 | 8-7 | 3 | 0 | Steve Blass | Andy Messersmith | Al Downing | Ramon Hernandez | | 83 | 69 | 14 |
| 1973-04-29 | vs LAN | 15 | L 1-2 | 8-7 | 3 | 18,083 | Dock Ellis | Claude Osteen | Claude Osteen | Dock Ellis | | 84 | 71 | 13 |
| 1973-05-01 | @ SFN | 16 | L 7-8 | 8-8 | 3 | 7,972 | Bob Moose | Ron Bryant | Elias Sosa | Ramon Hernandez | | 91 | 79 | 12 |
| 1973-05-02 | @ SFN | 17 | W 2-1 | 9-8 | 3 | 4,818 | Luke Walker | Jim Barr | Luke Walker | Jim Barr | Dave Giusti | 93 | 80 | 13 |
| 1973-05-03 | @ SFN | 18 | W 14-5 | 10-8 | 2 | 4,198 | Nelson Briles | Jim Willoughby | Nelson Briles | Jim Willoughby | | 107 | 85 | 22 |
| 1973-05-04 | @ SDN | 19 | W 12-6 | 11-8 | 2 | 9,595 | Steve Blass | Fred Norman | Steve Blass | Fred Norman | | 119 | 91 | 28 |
| 1973-05-05 | @ SDN | 20 | L 5-6 | 11-9 | 2 | 10,619 | Dock Ellis | Mike Corkins | Vicente Romo | Dock Ellis | | 124 | 97 | 27 |
| 1973-05-06 | @ SDN | 21 | L 0-8 | 11-10 | 2 | 7,176 | Bob Moose | Mike Caldwell | Mike Caldwell | Bob Moose | | 124 | 105 | 19 |
| 1973-05-07 | @ LAN | 22 | W 5-4 | 12-10 | 1 | 17,745 | Luke Walker | Don Sutton | Bob Johnson | Don Sutton | Jim Rooker | 129 | 109 | 20 |
| 1973-05-08 | @ LAN | 23 | L 4-7 | 12-11 | 2 | 13,620 | Nelson Briles | Andy Messersmith | Andy Messersmith | Nelson Briles | Jim Brewer | 133 | 116 | 17 |
| 1973-05-09 | @ LAN | 24 | L 5-8 | 12-12 | 3 | 17,509 | Steve Blass | Claude Osteen | Claude Osteen | Steve Blass | George Culver | 138 | 124 | 14 |
| 1973-05-11 | vs NYN | 25 | L 3-4 | 12-13 | 3 | 17,564 | Dock Ellis | Harry Parker | Harry Parker | Dock Ellis | Tug McGraw | 141 | 128 | 13 |
| 1973-05-12 | vs NYN | 26 | L 0-6 | 12-14 | 4 | 13,058 | Bob Moose | Tom Seaver | Tom Seaver | Bob Moose | | 141 | 134 | 7 |
| 1973-05-13 | vs NYN | 27 | L 4-6 | 12-15 | 4 | 14,310 | Luke Walker | Jim McAndrew | Jim McAndrew | Luke Walker | Tug McGraw | 145 | 140 | 5 |
| 1973-05-14 | vs MON | 28 | L 2-3 | 12-16 | 4 | 6,327 | Nelson Briles | Steve Renko | Tom Walker | Nelson Briles | | 147 | 143 | 4 |
| 1973-05-15 | vs MON | 29 | W 9-8 | 13-16 | 4 | 5,441 | Steve Blass | Ernie McAnally | Dave Giusti | Joe Gilbert | | 156 | 151 | 5 |
| 1973-05-16 | vs PHI | 30 | L 2-5 | 13-17 | 4 | 6,885 | Dock Ellis | Wayne Twitchell | Wayne Twitchell | Dock Ellis | Mac Scarce | 158 | 156 | 2 |
| 1973-05-17 | vs PHI | 31 | W 5-2 | 14-17 | 4 | 6,885 | Bob Moose | Steve Carlton | Bob Moose | Steve Carlton | Jim Rooker | 163 | 158 | 5 |
| 1973-05-18 | @ NYN | 32 | L 3-4 | 14-18 | 4 | 34,565 | Luke Walker | Tom Seaver | Tom Seaver | Luke Walker | | 166 | 162 | 4 |
| 1973-05-19 | @ NYN | 33 | W 4-1 | 15-18 | 3 | 32,622 | Nelson Briles | Jon Matlack | Dave Giusti | Tug McGraw | | 170 | 163 | 7 |
| 1973-05-21 | @ PHI | 34 | W 5-4 | 16-18 | 3 | 9,010 | Steve Blass | Steve Carlton | Steve Blass | Mac Scarce | Dave Giusti | 175 | 167 | 8 |
| 1973-05-22 | @ PHI | 35 | L 4-7 | 16-19 | 4 | 11,617 | Dock Ellis | Wayne Twitchell | Wayne Twitchell | Dock Ellis | | 179 | 174 | 5 |
| 1973-05-25 | vs HOU | 36 | L 2-7 | 16-20 | 4 | 13,956 | Bob Moose | Jerry Reuss | Jerry Reuss | Bob Moose | | 181 | 181 | 0 |
| 1973-05-26 | vs HOU | 37 | W 7-2 | 17-20 | 4 | 15,768 | Nelson Briles | Ken Forsch | Nelson Briles | Ken Forsch | Dave Giusti | 188 | 183 | 5 |
| 1973-05-27 | vs HOU | 38 | L 2-6 | 17-21 | 4 | 15,386 | Steve Blass | Dave Roberts | Dave Roberts | Steve Blass | | 190 | 189 | 1 |
| 1973-05-28 | vs HOU | 39 | W 4-2 | 18-21 | 4 | 21,546 | Dock Ellis | Don Wilson | Dock Ellis | Don Wilson | Dave Giusti | 194 | 191 | 3 |
| 1973-05-29 | vs ATL | 40 | W 6-1 | 19-21 | 3 | 7,911 | Luke Walker | Carl Morton | Luke Walker | Carl Morton | Jim Rooker | 200 | 192 | 8 |
| 1973-05-30 | vs ATL | 41 | W 4-2 | 20-21 | 3 | 7,963 | Bob Moose | Ron Reed | Bob Moose | Ron Reed | | 204 | 194 | 10 |
| 1973-05-31 | vs ATL | 42 | W 3-1 | 21-21 | 2 | 10,446 | Nelson Briles | Gary Gentry | Nelson Briles | Gary Gentry | | 207 | 195 | 12 |
| 1973-06-01 | vs CIN | 43 | W 9-6 | 22-21 | 2 | 24,213 | Steve Blass | Jim McGlothlin | Steve Blass | Ed Sprague | Dave Giusti | 216 | 201 | 15 |
| 1973-06-02 | vs CIN | 44 | W 4-3 | 23-21 | 2 | 19,212 | Dock Ellis | Jack Billingham | Dock Ellis | Jack Billingham | Dave Giusti | 220 | 204 | 16 |
| 1973-06-03 | vs CIN | 45 | L 1-5 | 23-22 | 2 | 22,450 | Luke Walker | Clay Carroll | Clay Carroll | Luke Walker | Pedro Borbon | 221 | 209 | 12 |
| 1973-06-04 | vs SFN | 46 | L 2-7 | 23-23 | 2 | 12,570 | Bob Moose | Tom Bradley | Tom Bradley | Bob Moose | | 223 | 216 | 7 |
| 1973-06-05 | vs SFN | 47 | L 2-3 | 23-24 | 2 | 14,975 | Nelson Briles | Ron Bryant | Ron Bryant | Nelson Briles | Randy Moffitt | 225 | 219 | 6 |
| 1973-06-06 | vs SFN | 48 | L 7-9 | 23-25 | 3 | 13,884 | Steve Blass | Juan Marichal | Charlie Williams | Jim Rooker | Randy Moffitt | 232 | 228 | 4 |
| 1973-06-08 | @ HOU | 49 | L 3-4 | 23-26 | 4 | 25,486 | Dock Ellis | Ken Forsch | Ken Forsch | Dock Ellis | Jim Ray | 235 | 232 | 3 |
| 1973-06-09 | @ HOU | 50 | W 4-1 | 24-26 | 3 | 29,716 | Bob Moose | Don Wilson | Bob Moose | Don Wilson | | 239 | 233 | 6 |
| 1973-06-10 | @ HOU | 51 | L 1-7 | 24-27 | 3 | 23,057 | Nelson Briles | Jerry Reuss | Jerry Reuss | Nelson Briles | | 240 | 240 | 0 |
| 1973-06-11 | @ ATL | 52 | L 7-9 | 24-28 | 4 | 6,878 | Steve Blass | Carl Morton | Carl Morton | Steve Blass | Ron Schueler | 247 | 249 | -2 |
| 1973-06-12 | @ ATL | 53 | L 2-4 | 24-29 | 5 | 10,418 | Luke Walker | Phil Niekro | Phil Niekro | Luke Walker | | 249 | 253 | -4 |
| 1973-06-13 | @ ATL | 54 | L 3-18 | 24-30 | 5 | 9,553 | Dock Ellis | Ron Reed | Ron Reed | Dock Ellis | | 252 | 271 | -19 |
| 1973-06-15 | @ CIN | 55 | L 0-6 | 24-31 | 5 | 27,029 | Bob Moose | Fred Norman | Fred Norman | Bob Moose | | 252 | 277 | -25 |
| 1973-06-16 | @ CIN | 56 | W 5-0 | 25-31 | 5 | 39,106 | Nelson Briles | Don Gullett | Nelson Briles | Don Gullett | | 257 | 277 | -20 |
| 1973-06-17 | @ CIN | 57 | L 1-3 | 25-33 | 5 | 0 | Luke Walker | Jack Billingham | Jack Billingham | Luke Walker | Tom Hall | 258 | 280 | -22 |
| 1973-06-17 | @ CIN | 58 | L 1-5 | 25-33 | 5 | 50,232 | Tom Dettore | Ross Grimsley | Ross Grimsley | Tom Dettore | | 259 | 285 | -26 |
| 1973-06-18 | vs CHN | 59 | W 3-1 | 26-33 | 5 | 11,470 | Dock Ellis | Fergie Jenkins | Dock Ellis | Fergie Jenkins | | 262 | 286 | -24 |
| 1973-06-19 | vs CHN | 60 | L 3-6 | 27-34 | 6 | 0 | Bob Johnson | Larry Gura | Larry Gura | Bob Johnson | Jack Aker | 265 | 292 | -27 |
| 1973-06-19 | vs CHN | 61 | W 4-3 | 27-34 | 6 | 28,256 | Bob Moose | Bill Bonham | Dave Giusti | Bob Locker | | 269 | 295 | -26 |
| 1973-06-20 | vs CHN | 62 | L 3-5 | 27-35 | 6 | 17,895 | Nelson Briles | Rick Reuschel | Rick Reuschel | Nelson Briles | Jack Aker | 272 | 300 | -28 |
| 1973-06-21 | vs NYN | 63 | W 2-1 | 28-35 | 6 | 10,099 | Luke Walker | Jerry Koosman | Luke Walker | Buzz Capra | | 274 | 301 | -27 |
| 1973-06-22 | vs NYN | 64 | L 4-5 | 28-36 | 6 | 21,129 | Steve Blass | George Stone | George Stone | Steve Blass | | 278 | 306 | -28 |
| 1973-06-23 | vs NYN | 65 | W 3-2 | 29-36 | 6 | 24,337 | Dock Ellis | Jim McAndrew | Ramon Hernandez | Phil Hennigan | | 281 | 308 | -27 |
| 1973-06-24 | vs NYN | 66 | L 2-5 | 29-37 | 6 | 20,984 | Bob Moose | Tom Seaver | Tom Seaver | Bob Moose | | 283 | 313 | -30 |
| 1973-06-25 | @ MON | 67 | W 8-6 | 31-37 | 6 | 0 | Bob Johnson | Ernie McAnally | Dave Giusti | Ernie McAnally | | 291 | 319 | -28 |
| 1973-06-25 | @ MON | 68 | W 3-1 | 31-37 | 6 | 24,402 | Nelson Briles | John Strohmayer | Nelson Briles | John Strohmayer | | 294 | 320 | -26 |
| 1973-06-26 | @ MON | 69 | L 3-10 | 31-38 | 6 | 12,806 | Luke Walker | Bill Stoneman | Bill Stoneman | Luke Walker | Mike Marshall | 297 | 330 | -33 |
| 1973-06-27 | vs SLN | 70 | L 4-15 | 31-39 | 6 | 33,041 | Jim Rooker | Reggie Cleveland | Reggie Cleveland | Jim Rooker | | 301 | 345 | -44 |
| 1973-06-28 | vs SLN | 71 | W 6-0 | 32-39 | 5 | 34,471 | Dock Ellis | Rick Wise | Dock Ellis | Rick Wise | | 307 | 345 | -38 |
| 1973-06-29 | vs MON | 72 | W 4-0 | 33-39 | 5 | 26,638 | Bob Moose | Ernie McAnally | Bob Moose | Ernie McAnally | | 311 | 345 | -34 |
| 1973-06-30 | vs MON | 73 | W 5-1 | 34-39 | 5 | 11,676 | Nelson Briles | Balor Moore | Nelson Briles | Balor Moore | Ramon Hernandez | 316 | 346 | -30 |
| 1973-07-01 | vs MON | 74 | W 6-2 | 36-39 | 3 | 0 | Luke Walker | Bill Stoneman | Luke Walker | Bill Stoneman | Bob Johnson | 322 | 348 | -26 |
| 1973-07-01 | vs MON | 75 | W 8-4 | 36-39 | 3 | 24,984 | Jim Rooker | Mike Torrez | Jim Rooker | Mike Torrez | Dave Giusti | 330 | 352 | -22 |
| 1973-07-03 | @ SLN | 76 | L 0-4 | 36-41 | 5 | 0 | Dock Ellis | Rick Wise | Rick Wise | Dock Ellis | | 330 | 356 | -26 |
| 1973-07-03 | @ SLN | 77 | L 6-7 | 36-41 | 5 | 28,449 | Steve Blass | Rich Folkers | Rich Folkers | Steve Blass | Diego Segui | 336 | 363 | -27 |
| 1973-07-04 | @ SLN | 78 | L 3-11 | 36-42 | 5 | 12,671 | Bob Moose | Tom Murphy | Tom Murphy | Bob Moose | | 339 | 374 | -35 |
| 1973-07-05 | @ SLN | 79 | W 3-2 | 37-42 | 5 | 14,652 | Nelson Briles | Alan Foster | Nelson Briles | Orlando Pena | | 342 | 376 | -34 |
| 1973-07-06 | @ LAN | 80 | L 2-3 | 37-43 | 5 | 28,011 | Luke Walker | Don Sutton | Don Sutton | Luke Walker | | 344 | 379 | -35 |
| 1973-07-07 | @ LAN | 81 | L 6-8 | 37-44 | 5 | 33,197 | Jim Rooker | Andy Messersmith | Doug Rau | John Lamb | Jim Brewer | 350 | 387 | -37 |
| 1973-07-08 | @ LAN | 82 | L 2-3 | 37-45 | 5 | 24,144 | Dock Ellis | Tommy John | Pete Richert | Dave Giusti | | 352 | 390 | -38 |
| 1973-07-10 | @ SDN | 83 | W 4-3 | 38-45 | 4 | 12,233 | Bob Moose | Rich Troedson | Bob Johnson | Rich Troedson | John Lamb | 356 | 393 | -37 |
| 1973-07-11 | @ SDN | 84 | W 10-2 | 39-45 | 4 | 4,763 | Nelson Briles | Steve Arlin | Nelson Briles | Steve Arlin | | 366 | 395 | -29 |
| 1973-07-12 | @ SDN | 85 | W 4-0 | 40-45 | 4 | 2,865 | Luke Walker | Clay Kirby | Luke Walker | Clay Kirby | | 370 | 395 | -25 |
| 1973-07-13 | @ SFN | 86 | L 2-5 | 40-46 | 4 | 10,842 | Dock Ellis | Tom Bradley | Tom Bradley | Dock Ellis | | 372 | 400 | -28 |
| 1973-07-14 | @ SFN | 87 | W 7-2 | 41-46 | 4 | 9,458 | Jim Rooker | Ron Bryant | Jim Rooker | Ron Bryant | | 379 | 402 | -23 |
| 1973-07-15 | @ SFN | 88 | L 0-12 | 41-47 | 4 | 12,851 | Bob Moose | Juan Marichal | Juan Marichal | Bob Moose | | 379 | 414 | -35 |
| 1973-07-16 | vs LAN | 89 | L 0-1 | 41-48 | 4 | 16,570 | Nelson Briles | Don Sutton | Don Sutton | Nelson Briles | | 379 | 415 | -36 |
| 1973-07-17 | vs LAN | 90 | L 4-8 | 41-49 | 5 | 17,389 | Luke Walker | Andy Messersmith | Andy Messersmith | Luke Walker | Jim Brewer | 383 | 423 | -40 |
| 1973-07-18 | vs LAN | 91 | W 3-2 | 42-49 | 4 | 24,248 | Dock Ellis | Tommy John | Dock Ellis | Tommy John | Dave Giusti | 386 | 425 | -39 |
| 1973-07-20 | vs SDN | 92 | W 5-4 | 44-49 | 4 | 0 | John Morlan | Randy Jones | Dave Giusti | Mike Caldwell | | 391 | 429 | -38 |
| 1973-07-20 | vs SDN | 93 | W 7-0 | 44-49 | 4 | 25,832 | Jim Rooker | Rich Troedson | Jim Rooker | Rich Troedson | | 398 | 429 | -31 |
| 1973-07-22 | vs SDN | 94 | W 3-1 | 46-49 | 3 | 0 | Nelson Briles | Steve Arlin | Nelson Briles | Steve Arlin | Dave Giusti | 401 | 430 | -29 |
| 1973-07-22 | vs SDN | 95 | W 13-7 | 46-49 | 3 | 22,425 | Luke Walker | Clay Kirby | Luke Walker | Clay Kirby | John Lamb | 414 | 437 | -23 |
| 1973-07-26 | @ CHN | 96 | W 3-2 | 47-49 | 4 | 35,770 | Dock Ellis | Rick Reuschel | Dock Ellis | Rick Reuschel | Dave Giusti | 417 | 439 | -22 |
| 1973-07-27 | @ CHN | 97 | W 10-6 | 48-49 | 4 | 22,045 | Nelson Briles | Larry Gura | Nelson Briles | Larry Gura | Dave Giusti | 427 | 445 | -18 |
| 1973-07-28 | vs PHI | 98 | L 0-5 | 48-50 | 4 | 14,630 | Jim Rooker | Wayne Twitchell | Wayne Twitchell | Jim Rooker | | 427 | 450 | -23 |
| 1973-07-29 | vs PHI | 99 | W 5-2 | 50-50 | 4 | 0 | John Morlan | Dick Ruthven | Ramon Hernandez | Dick Ruthven | | 432 | 452 | -20 |
| 1973-07-29 | vs PHI | 100 | W 5-2 | 50-50 | 4 | 26,947 | Luke Walker | Barry Lersch | Luke Walker | Barry Lersch | Dave Giusti | 437 | 454 | -17 |
| 1973-07-30 | vs PHI | 101 | L 0-1 | 50-51 | 4 | 17,220 | Bob Moose | Steve Carlton | Steve Carlton | Bob Moose | | 437 | 455 | -18 |
| 1973-07-31 | @ NYN | 102 | W 4-1 | 51-51 | 4 | 24,322 | Dock Ellis | Jerry Koosman | Dock Ellis | Jerry Koosman | Ramon Hernandez | 441 | 456 | -15 |
| 1973-08-01 | @ NYN | 103 | L 0-3 | 51-53 | 4 | 0 | Steve Blass | Tom Seaver | Tom Seaver | Steve Blass | | 441 | 459 | -18 |
| 1973-08-01 | @ NYN | 104 | L 2-5 | 51-53 | 4 | 27,189 | Nelson Briles | George Stone | George Stone | Nelson Briles | Harry Parker | 443 | 464 | -21 |
| 1973-08-02 | @ NYN | 105 | L 1-5 | 51-54 | 4 | 13,429 | Jim Rooker | Ray Sadecki | Ray Sadecki | Jim Rooker | Tug McGraw | 444 | 469 | -25 |
| 1973-08-03 | @ PHI | 106 | W 3-1 | 52-54 | 4 | 24,152 | John Morlan | Steve Carlton | John Morlan | Steve Carlton | Ramon Hernandez | 447 | 470 | -23 |
| 1973-08-04 | @ PHI | 107 | L 5-11 | 53-55 | 4 | 0 | Luke Walker | Ken Brett | Ken Brett | Luke Walker | | 452 | 481 | -29 |
| 1973-08-04 | @ PHI | 108 | W 11-4 | 53-55 | 4 | 48,294 | Bob Moose | Jim Lonborg | Ramon Hernandez | Jim Lonborg | | 463 | 485 | -22 |
| 1973-08-05 | @ PHI | 109 | W 4-1 | 54-55 | 4 | 31,157 | Dock Ellis | Wayne Twitchell | Dock Ellis | Wayne Twitchell | Dave Giusti | 467 | 486 | -19 |
| 1973-08-07 | vs HOU | 110 | L 0-2 | 54-56 | 4 | 13,841 | Nelson Briles | Don Wilson | Don Wilson | Nelson Briles | | 467 | 488 | -21 |
| 1973-08-08 | vs HOU | 111 | W 4-3 | 55-56 | 3 | 15,745 | Jim Rooker | Dave Roberts | Jim Rooker | Dave Roberts | Bob Johnson | 471 | 491 | -20 |
| 1973-08-10 | vs ATL | 112 | L 4-5 | 55-57 | 3 | 25,781 | Dock Ellis | Phil Niekro | Phil Niekro | Dock Ellis | | 475 | 496 | -21 |
| 1973-08-11 | vs ATL | 113 | L 3-9 | 55-58 | 3 | 21,365 | John Morlan | Roric Harrison | Roric Harrison | John Morlan | Tom House | 478 | 505 | -27 |
| 1973-08-12 | vs ATL | 114 | W 5-2 | 56-58 | 3 | 28,718 | Bob Moose | Ron Schueler | Bob Moose | Ron Schueler | | 483 | 507 | -24 |
| 1973-08-13 | vs CIN | 115 | W 3-2 | 57-58 | 3 | 15,396 | Nelson Briles | Fred Norman | Nelson Briles | Fred Norman | Dave Giusti | 486 | 509 | -23 |
| 1973-08-14 | vs CIN | 116 | L 4-5 | 57-59 | 3 | 17,841 | Jim Rooker | Ross Grimsley | Clay Carroll | Ramon Hernandez | Tom Hall | 490 | 514 | -24 |
| 1973-08-15 | vs CIN | 117 | L 0-1 | 57-60 | 3 | 20,903 | Dock Ellis | Jack Billingham | Jack Billingham | Dock Ellis | | 490 | 515 | -25 |
| 1973-08-17 | vs SFN | 118 | L 3-5 | 57-61 | 3 | 15,789 | Bob Moose | Ron Bryant | Ron Bryant | Bob Moose | Elias Sosa | 493 | 520 | -27 |
| 1973-08-18 | vs SFN | 119 | W 6-5 | 58-61 | 3 | 19,569 | Nelson Briles | Jim Barr | Nelson Briles | Jim Barr | Dave Giusti | 499 | 525 | -26 |
| 1973-08-19 | vs SFN | 120 | W 5-0 | 59-61 | 3 | 23,640 | Jim Rooker | Juan Marichal | Jim Rooker | Juan Marichal | | 504 | 525 | -21 |
| 1973-08-20 | @ HOU | 121 | L 2-10 | 59-62 | 3 | 11,057 | Dock Ellis | J.R. Richard | J.R. Richard | Dock Ellis | | 506 | 535 | -29 |
| 1973-08-21 | @ HOU | 122 | W 6-3 | 60-62 | 2 | 11,094 | John Morlan | Don Wilson | John Morlan | Don Wilson | | 512 | 538 | -26 |
| 1973-08-22 | @ HOU | 123 | W 4-0 | 61-62 | 2 | 10,746 | Bob Moose | Tom Griffin | Bob Moose | Tom Griffin | | 516 | 538 | -22 |
| 1973-08-24 | @ ATL | 124 | L 2-3 | 61-63 | 2 | 15,680 | Nelson Briles | Carl Morton | Adrian Devine | Dave Giusti | | 518 | 541 | -23 |
| 1973-08-25 | @ ATL | 125 | W 6-5 | 62-63 | 2 | 20,103 | Jim Rooker | Phil Niekro | Dave Giusti | Gary Neibauer | | 524 | 546 | -22 |
| 1973-08-26 | @ ATL | 126 | L 6-8 | 62-64 | 2 | 26,113 | Dock Ellis | Roric Harrison | Roric Harrison | Dock Ellis | Adrian Devine | 530 | 554 | -24 |
| 1973-08-28 | @ CIN | 127 | W 8-3 | 63-64 | 2 | 31,729 | Bob Moose | Ross Grimsley | Bob Moose | Ross Grimsley | Bob Johnson | 538 | 557 | -19 |
| 1973-08-29 | @ CIN | 128 | L 3-5 | 63-65 | 2 | 30,032 | Nelson Briles | Jack Billingham | Jack Billingham | Nelson Briles | | 541 | 562 | -21 |
| 1973-08-31 | vs CHN | 129 | W 7-0 | 65-65 | 2 | 0 | Jim Rooker | Rick Reuschel | Jim Rooker | Rick Reuschel | | 548 | 562 | -14 |
| 1973-08-31 | vs CHN | 130 | W 5-2 | 65-65 | 2 | 35,884 | John Morlan | Fergie Jenkins | Bob Johnson | Fergie Jenkins | Ramon Hernandez | 553 | 564 | -11 |
| 1973-09-01 | vs CHN | 131 | W 1-0 | 66-65 | 1 | 13,484 | Bruce Kison | Burt Hooton | Dave Giusti | Burt Hooton | | 554 | 564 | -10 |
| 1973-09-02 | vs CHN | 132 | L 3-5 | 66-66 | 2 | 19,130 | Bob Moose | Bill Bonham | Bob Locker | Ramon Hernandez | | 557 | 569 | -12 |
| 1973-09-03 | vs SLN | 133 | W 5-4 | 67-67 | 3 | 0 | Nelson Briles | Reggie Cleveland | Dave Giusti | Eddie Fisher | | 562 | 573 | -11 |
| 1973-09-03 | vs SLN | 134 | L 3-8 | 67-67 | 3 | 43,839 | Luke Walker | Rich Folkers | Rich Folkers | Luke Walker | Orlando Pena | 565 | 581 | -16 |
| 1973-09-04 | vs SLN | 135 | L 2-4 | 67-68 | 3 | 16,280 | Jim Rooker | Mike Nagy | John Andrews | Jim Rooker | Al Hrabosky | 567 | 585 | -18 |
| 1973-09-05 | vs SLN | 136 | L 3-5 | 67-69 | 3 | 18,894 | John Morlan | Alan Foster | Alan Foster | John Morlan | Diego Segui | 570 | 590 | -20 |
| 1973-09-07 | @ PHI | 137 | W 10-8 | 68-69 | 3 | 15,233 | Bruce Kison | Ken Brett | Bob Johnson | Mac Scarce | Ramon Hernandez | 580 | 598 | -18 |
| 1973-09-08 | @ PHI | 138 | W 5-3 | 69-69 | 3 | 16,320 | Bob Moose | Steve Carlton | Bob Moose | Steve Carlton | Dave Giusti | 585 | 601 | -16 |
| 1973-09-09 | @ PHI | 139 | L 7-8 | 69-70 | 3 | 14,356 | Nelson Briles | Dick Ruthven | Mac Scarce | Bob Johnson | | 592 | 609 | -17 |
| 1973-09-10 | @ CHN | 140 | W 11-3 | 70-70 | 3 | 7,255 | Jim Rooker | Rick Reuschel | Jim Rooker | Rick Reuschel | | 603 | 612 | -9 |
| 1973-09-11 | @ CHN | 141 | L 0-2 | 70-71 | 3 | 8,516 | Steve Blass | Burt Hooton | Burt Hooton | Steve Blass | | 603 | 614 | -11 |
| 1973-09-12 | @ CHN | 142 | W 4-2 | 71-71 | 2 | 9,857 | Bruce Kison | Mike Paul | Bruce Kison | Mike Paul | Dave Giusti | 607 | 616 | -9 |
| 1973-09-13 | @ CHN | 143 | W 6-1 | 72-71 | 2 | 7,375 | Bob Moose | Milt Pappas | Bob Moose | Milt Pappas | Ramon Hernandez | 613 | 617 | -4 |
| 1973-09-14 | @ SLN | 144 | W 3-1 | 73-71 | 2 | 32,630 | Nelson Briles | Reggie Cleveland | Nelson Briles | Reggie Cleveland | Ramon Hernandez | 616 | 618 | -2 |
| 1973-09-15 | @ SLN | 145 | W 7-4 | 74-71 | 2 | 28,219 | Jim Rooker | Mike Nagy | Jim Rooker | Mike Nagy | Ramon Hernandez | 623 | 622 | 1 |
| 1973-09-16 | @ SLN | 146 | L 3-7 | 74-72 | 2 | 31,938 | Steve Blass | Alan Foster | Alan Foster | Luke Walker | Al Hrabosky | 626 | 629 | -3 |
| 1973-09-17 | vs NYN | 147 | W 10-3 | 75-72 | 2 | 15,000 | Bruce Kison | Tom Seaver | Bruce Kison | Tom Seaver | Chris Zachary | 636 | 632 | 4 |
| 1973-09-18 | vs NYN | 148 | L 5-6 | 75-73 | 2 | 12,336 | Bob Moose | Jon Matlack | Tug McGraw | Ramon Hernandez | Buzz Capra | 641 | 638 | 3 |
| 1973-09-19 | @ NYN | 149 | L 3-7 | 75-74 | 2 | 29,240 | Nelson Briles | George Stone | George Stone | Nelson Briles | Tug McGraw | 644 | 645 | -1 |
| 1973-09-20 | @ NYN | 150 | L 3-4 | 75-75 | 2 | 24,855 | Jim Rooker | Jerry Koosman | Ray Sadecki | Luke Walker | | 647 | 649 | -2 |
| 1973-09-21 | @ NYN | 151 | L 2-10 | 75-76 | 3 | 51,381 | Steve Blass | Tom Seaver | Tom Seaver | Steve Blass | | 649 | 659 | -10 |
| 1973-09-23 | @ MON | 152 | W 6-3 | 77-76 | 2 | 0 | Bruce Kison | Bill Stoneman | Bruce Kison | Bill Stoneman | Ramon Hernandez | 655 | 662 | -7 |
| 1973-09-23 | @ MON | 153 | W 7-4 | 77-76 | 2 | 26,178 | Dock Ellis | Mike Torrez | Dock Ellis | Mike Torrez | Dave Giusti | 662 | 666 | -4 |
| 1973-09-24 | @ MON | 154 | L 4-5 | 78-77 | 2 | 0 | Bob Moose | Steve Renko | Steve Renko | Bob Moose | Mike Marshall | 666 | 671 | -5 |
| 1973-09-24 | @ MON | 155 | W 3-0 | 78-77 | 2 | 20,168 | Nelson Briles | Ernie McAnally | Nelson Briles | Ernie McAnally | Dave Giusti | 669 | 671 | -2 |
| 1973-09-25 | vs PHI | 156 | L 1-2 | 78-78 | 2 | 13,312 | Jim Rooker | Steve Carlton | Steve Carlton | Jim Rooker | | 670 | 673 | -3 |
| 1973-09-26 | vs PHI | 157 | W 13-2 | 79-78 | 2 | 8,991 | Jim McKee | Jim Lonborg | Bob Moose | Jim Lonborg | Bob Johnson | 683 | 675 | 8 |
| 1973-09-27 | vs PHI | 158 | L 2-3 | 79-79 | 2 | 11,577 | Bruce Kison | Barry Lersch | George Culver | Chris Zachary | Mike Wallace | 685 | 678 | 7 |
| 1973-09-28 | vs MON | 159 | L 2-3 | 79-80 | 3 | 27,804 | Dock Ellis | Steve Renko | Mike Marshall | Dock Ellis | | 687 | 681 | 6 |
| 1973-09-29 | vs MON | 160 | L 4-6 | 79-81 | 4 | 9,816 | Nelson Briles | Steve Rogers | Steve Rogers | Jim McKee | Mike Marshall | 691 | 687 | 4 |
| 1973-09-30 | vs MON | 161 | W 10-2 | 80-81 | 4 | 33,376 | Jim Rooker | Ernie McAnally | Jim Rooker | Ernie McAnally | | 701 | 689 | 12 |
| 1973-10-01 | vs SDN | 162 | L 3-4 | 80-82 | 4 | 2,572 | Bruce Kison | Randy Jones | Randy Jones | Bob Moose | Mike Corkins | 704 | 693 | 11 |