| 1. Round | 17/03/2018 | Seattle Sounders 2 | - | Portland Timbers 2 | 2:1 | ||||
| 1. Round | 25/03/2018 | Colorado Springs Switchbacks | - | Portland Timbers 2 | 0:1 | ||||
| 1. Round | 31/03/2018 | Real Monarchs SLC | - | Portland Timbers 2 | 4:2 | ||||
| 4. Round | 03/06/2018 | San Antonio FC | - | Portland Timbers 2 | 2:1 | ||||
| 4. Round | 14/06/2018 | Portland Timbers 2 | - | OKC Energy FC | 1:2 | ||||
| 4. Round | 17/06/2018 | Portland Timbers 2 | - | Colorado Springs Switchbacks | 1:4 |  |
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| 4. Round | 01/07/2018 | Reno 1868 FC | - | Portland Timbers 2 | 1:0 | ||||
| 5. Round | 08/07/2018 | Portland Timbers 2 | - | Fresno FC | 2:4 | ||||
| 5. Round | 15/07/2018 | Portland Timbers 2 | - | Swope Park Rangers | 2:1 | ||||
| 5. Round | 22/07/2018 | Portland Timbers 2 | - | Las Vegas Lights FC | 1:2 | ||||
| 6. Round | 12/08/2018 | Swope Park Rangers | - | Portland Timbers 2 | 0:2 | ||||
| 7. Round | 23/09/2018 | Fresno FC | - | Portland Timbers 2 | 2:2 | ||||
| 7. Round | 30/09/2018 | Sacramento Republic | - | Portland Timbers 2 | 1:0 | ||||
| 8. Round | 04/10/2018 | Portland Timbers 2 | - | Reno 1868 FC | 0:2 |  |
USA