| 1. Round | 17/03/2018 | Seattle Sounders 2 | - | Portland Timbers 2 | 2:1 | ||||
| 1. Round | 25/03/2018 | Swope Park Rangers | - | Seattle Sounders 2 | 4:2 | ||||
| 1. Round | 29/03/2018 | Seattle Sounders 2 | - | Fresno FC | 0:1 | ||||
| 2. Round | 12/04/2018 | Seattle Sounders 2 | - | Real Monarchs SLC | 1:3 | ||||
| 5. Round | 08/07/2018 | Seattle Sounders 2 | - | Reno 1868 FC | 1:2 | ||||
| 5. Round | 15/07/2018 | Real Monarchs SLC | - | Seattle Sounders 2 | 2:0 | ||||
| 5. Round | 21/07/2018 | Phoenix Rising | - | Seattle Sounders 2 | 1:0 |
USA