Additions
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 07/2025 |  | Mateo García | DF | |||
| 07/2025 | | Aarón Del Valle | FW |  | Athletic Club U15 | U15 |
| 07/2025 |  | Idrissa Bah | FW | | Athletic Club U15 | U15 |
Departures
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 07/2025 |  | Aitor León | DF |  | Athletic Club U19 | Bilbao U19 |
| 07/2025 | | Álex Torres | DF |  | Athletic Club B | Bilbao B |
| 07/2025 |  | Ilyas El Arbaoui | DF | | Athletic Club B | Bilbao B |
| 07/2025 | | Ibai | DF | | Athletic Club U19 | Bilbao U19 |
| 07/2025 | | Iker Quintero | DF |  | CD Basconia | CD Basconia |
| 07/2025 | | Adrián | MF | | Athletic Club B | Bilbao B |
| 07/2025 | | Ander Ezpeleta | MF | | CD Basconia | CD Basconia |
| 07/2025 | | Enzo | MF | | Athletic Club B | Bilbao B |
| 07/2025 | | Oihan Encinas | MF | | Athletic Club B | Bilbao B |
| 07/2025 | | Zabala | MF | | Athletic Club U19 | Bilbao U19 |
| 07/2025 | | Andrés | FW | | Athletic Club B | Bilbao B |
| 07/2025 | | Asier Torres | FW | | Athletic Club B | Bilbao B |
| 07/2025 |  | Yann Cissé | FW | | Athletic Club U19 | Bilbao U19 |
| 07/2025 | | Danel Narvarte | FW | | Athletic Club U19 | Bilbao U19 |