| 7. Round | 06/09/2018 | Seattle Sounders 2 | - | Tulsa Roughnecks | 4:4 | ||||
| 7. Round | 30/09/2018 | San Antonio FC | - | Seattle Sounders 2 | 3:1 | ||||
| 8. Round | 07/10/2018 | Orange County SC | - | Seattle Sounders 2 | 2:1 | ||||
| 8. Round | 11/10/2018 | Seattle Sounders 2 | - | Colorado Springs Switchbacks | 2:2 |  |
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| 8. Round | 14/10/2018 | Tulsa Roughnecks | - | Seattle Sounders 2 | 1:4 | |
Puerto Rico