| Month | Game | Strat Date | + | Away | Pitcher | Balance | At | Home | Pitcher | Balance |
| September | 1 | 9/9/2021 | HOH | Matt Boyd* | 3R | At | CHI | Jordan Lyles | 3L | |
| September | 2 | 9/10/2021 | HOH | Nathan Eovaldi | 2L | At | CHI | Chris Flexen | 4L | |
| September | 3 | 9/11/2021 | HOH | Zach Thompson | 7R | At | CHI | Jesse Chavez | 1R | |
| September | 4 | 9/12/2021 | CHI | John Means* | E | At | CRC | Triston McKenzie | 1L | |
| September | 5 | 9/13/2021 | CHI | Wade Miley* | 4L | At | CRC | Kevin Gausman | E | |
| September | 6 | 9/14/2021 | CHI | Aaron Civale | 4L | At | CRC | Jake Odorizzi | 1R | |
| September | OFF | 9/15/2021 | ||||||||
| September | 7 | 9/16/2021 | + | CHI | Jake Woodford | 6R | At | TAM | Tyler Glasnow | 2L |
| September | 8 | 9/17/2021 | + | CHI | Jesse Chavez | 1R | At | TAM | Trevor Rogers* | 4R |
| September | 9 | 9/18/2021 | + | CHI | Chris Flexen | 4L | At | TAM | Yusei Kikuchi* | 7L |
| September | 10 | 9/19/2021 | + | CHI | John Curtiss | E | At | TAM | Jose Urquidy | 5L |
| September | 11 | 9/20/2021 | + | CHI | Jordan Lyles | 3L | At | TAM | Johan Oviedo | 2R |
| September | 12 | 9/21/2021 | + | GGG | Dustin May | E | At | CHI | Jake Woodford | 6R |
| September | 13 | 9/22/2021 | + | GGG | John Gant | E | At | CHI | Wade Miley* | 4L |
| September | 14 | 9/23/2021 | + | GGG | Framber Valdez* | 1R | At | CHI | Chris Flexen | 4L |
| September | 15 | 9/24/2021 | + | GGG | Nick Pivetta | E | At | CHI | John Means* | E |
| September | OFF | 9/25/2021 | ||||||||
| September | 16 | 9/26/2021 | + | DYE | Miles Mikolas | E | At | CHI | Jordan Lyles | 3L |
| September | 17 | 9/27/2021 | + | DYE | Marcus Stroman | 1L | At | CHI | John Curtiss | E |
| September | 18 | 9/28/2021 | + | DYE | Anthony Desclafani | 3R | At | CHI | Jake Woodford | 6R |
| September | 19 | 9/29/2021 | + | DYE | Aaron Nola | 1L | At | CHI | John Means* | E |
| September | 20 | 9/30/2021 | + | DYE | Jack Flaherty | 5L | At | CHI | Wade Miley* | 4L |
| September | 21 | 10/1/2021 | + | CHI | Jordan Lyles | 3L | At | GGG | Dustin May | E |
| September | 22 | 10/2/2021 | + | CHI | John Curtiss | E | At | GGG | John Gant | E |
| September | 23 | 10/3/2021 | + | CHI | Jake Woodford | 6R | At | GGG | Cole Irvin* | 3R |
| September | 24 | 10/4/2021 | + | CHI | John Means* | E | At | GGG | Nick Pivetta | E |
| + Indicates In Division Game | ||||||||||