Additions
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 08/2017 |  | Steve Clark | GK | |||
| 08/2017 | | Paul Arriola | MF |  | Club Tijuana | Club Tijuana |
| 08/2017 | | Russell Canouse | MF |  | VfL Bochum | Bochum |
| 08/2017 |  | Zoltán Stieber | MF |  | 1. FC Kaiserslautern | K'lautern |
| 08/2017 |  | Bruno Miranda | FW |  | Universidad de Chile | Uni. de Chile |
| 06/2017 |  | Deshorn Brown | FW |  | Tampa Bay Rowdies | Tampa Bay |
| 05/2017 | | Chris Korb | DF | |||
| 02/2017 |  | Maxim Tissot | DF |  | Richmond Kickers | Richmond Kickers |
| 01/2017 |  | Sébastien Le Toux | FW | |||
| 01/2017 | | Ian Harkes | MF | |||
| 01/2017 | | Eric Klenofsky | GK | |||
| 01/2017 | | Chris Odoi-Atsem | DF |  | Loudoun United | Loudoun United |
| 01/2017 |  | José Ortiz | FW |  | CS Herediano | CS Herediano |
| 01/2017 | | Nolan Sheldon | AS-CO | |||
| 01/2017 | | Peter Gorka | PH-C |
Departures
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 08/2017 | | Bobby Boswell | DF |  | Atlanta United FC | Atlanta United |
| 08/2017 | | Lamar Neagle | MF |  | Seattle Sounders | Seattle SFC |
| 07/2017 | | José Ortiz | FW | | CS Herediano | CS Herediano |
| 07/2017 |  | Alhaji Kamara | FW |  | Al Taawoun | Al Taawoun |
| 05/2017 | | Maxim Tissot | DF |  | San Francisco Deltas | SF Deltas |
| 01/2017 | | Álvaro Saborío | FW |  | Deportivo Saprissa | Saprissa |
| 01/2017 | | Collin Martin | MF |  | Minnesota United FC | Minnesota Utd |
| 01/2017 |  | Kennedy Igboananike | FW |  | Örebro SK | Örebro SK |
| 01/2017 | | Davy Arnaud | AS-CO |  | Houston Dynamo | H. Dynamo |