Additions
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 07/2023 |  | Eric | GK |  | Athletic Club U19 | Bilbao U19 |
| 07/2023 | | Mikel Santos | GK | | Athletic Club U19 | Bilbao U19 |
| 07/2023 | | David Arredondo | MF | | Athletic Club U19 | Bilbao U19 |
| 07/2023 | | Gaizka Alboniga | MF | | Athletic Club U19 | Bilbao U19 |
| 07/2023 | | Peio Huestamendia | MF |  | Athletic Club U17 | U17 |
| 07/2023 | | Aimar Vicandi | FW | | Athletic Club U19 | Bilbao U19 |
| 07/2023 | | Julen Lartitegi | FW | |||
| 07/2023 | | Bittor Llopis | MA |
Departures
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 01/2024 | | Eric | GK |  | Athletic Club B | Bilbao B |
| 01/2024 | | Julen Lartitegi | FW | | Athletic Club B | Bilbao B |
| 01/2024 | | Manex Irizar | FW | | Athletic Club B | Bilbao B |