| Month | Game | Strat Date | + | Away | Pitcher | Balance | At | Home | Pitcher | Balance |
| September | 1 | 9/9/2018 | CUB | Jon Lester* | 6R | At | HUC | Jeremy Hellickson | 4L | |
| September | 2 | 9/10/2018 | CUB | Jake Odorizzi | E | At | HUC | Trevor Cahill | 2R | |
| September | 3 | 9/11/2018 | CUB | Kyle Hendricks | 2L | At | HUC | Blake Snell* | 2L | |
| September | 4 | 9/12/2018 | OAK | Jaime Barria | 6L | At | CUB | Julio Teheran | 2R | |
| September | 5 | 9/13/2018 | OAK | Brad Keller | 3R | At | CUB | Jon Gray | 3R | |
| September | 6 | 9/14/2018 | OAK | Anthony Desclafani | 6R | At | CUB | Jon Lester* | 6R | |
| September | OFF | 9/15/2018 | ||||||||
| September | 7 | 9/16/2018 | CUB | Jake Odorizzi | E | At | NYY | Carlos Martinez | 2R | |
| September | 8 | 9/17/2018 | CUB | Kyle Hendricks | 2L | At | NYY | Trevor Bauer | 2L | |
| September | 9 | 9/18/2018 | CUB | Julio Teheran | 2R | At | NYY | Seth Lugo | 4L | |
| September | 10 | 9/19/2018 | VRN | David Price* | 1L | At | CUB | Jon Gray | 3R | |
| September | 11 | 9/20/2018 | VRN | Gerrit Cole | 6L | At | CUB | Jon Lester* | 6R | |
| September | 12 | 9/21/2018 | VRN | Zach Eflin | 4R | At | CUB | Jake Odorizzi | E | |
| September | 13 | 9/22/2018 | CUB | Kyle Hendricks | 2L | At | CHI | Vince Velasquez | 7R | |
| September | 14 | 9/23/2018 | CUB | Julio Teheran | 2R | At | CHI | Masahiro Tanaka | 3L | |
| September | 15 | 9/24/2018 | CUB | Jon Gray | 3R | At | CHI | Robbie Ray* | 6L | |
| September | OFF | 9/25/2018 | ||||||||
| September | 16 | 9/26/2018 | + | CUB | Jon Lester* | 6R | At | BUR | Brett Anderson* | 2L |
| September | 17 | 9/27/2018 | + | CUB | Jake Odorizzi | E | At | BUR | Mike Minor* | 5R |
| September | 18 | 9/28/2018 | + | CUB | Kyle Hendricks | 2L | At | BUR | Zack Greinke | 2L |
| September | 19 | 9/29/2018 | + | CUB | Julio Teheran | 2R | At | BUR | J.A. Happ* | 6L |
| September | 20 | 9/30/2018 | + | CUB | Jon Gray | 3R | At | BUR | Walker Buehler | E |
| September | 21 | 10/1/2018 | + | DUB | Wei-Yin Chen* | 6L | At | CUB | Jon Lester* | 6R |
| September | 22 | 10/2/2018 | + | DUB | Justin Verlander | 2L | At | CUB | Jake Odorizzi | E |
| September | 23 | 10/3/2018 | + | DUB | Matt Strahm* | 5R | At | CUB | Kyle Hendricks | 2L |
| September | 24 | 10/4/2018 | + | DUB | Madison Bumgarner* | 2L | At | CUB | Julio Teheran | 2R |
| + Indicates In Division Game | ||||||||||