Additions
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 02/2018 |  | Xabi Sánchez | MA | |||
| 01/2018 | | Arriaga | FW | |||
| 08/2017 | | Aurtenetxe | DF | |||
| 08/2017 |  | Matej Šimić | DF |  | Muro CF | Muro CF |
| 07/2017 | | Nacho Zabal | GK |  | Arandina CF | Arandina CF |
| 07/2017 | | Tena | GK |  | Real Unión | Real Unión |
| 07/2017 | | De Eguino | DF |  | SD Zamudio | SD Zamudio |
| 07/2017 | | Héctor Sánchez | DF |  | CD Palencia | CD Palencia |
| 07/2017 | | Jon Agirrezabala | DF |  | Athletic Club B | Bilbao B |
| 07/2017 | | Jon Galarza | DF | |||
| 07/2017 | | Juaristi | DF |  | Barakaldo CF | Barakaldo CF |
| 07/2017 | | Aitor Ortega | MF | |||
| 07/2017 | | Gorka Iturraspe | MF | | Athletic Club B | Bilbao B |
| 07/2017 |  | Sebastián Setti | MF |  | UE Figueres | UE Figueres |
| 07/2017 | | Adrián Güemes | FW |  | Sestao River | Sestao River |
| 07/2017 | | Iván Arana | FW |  | SD Deusto | SD Deusto |
| 07/2017 | | Jon Ander | FW | |||
| 07/2017 | | Juan Martín | FW | | Sestao River | Sestao River |
| 07/2017 | | Mikel Zarrabeitia | FW |  | Club Portugalete | Portugalete |
| 07/2017 | | Mújika | FW | | Real Unión | Real Unión |
| 07/2017 | | Ubis | FW |  | Arenas de Getxo | Arenas de Getxo |
| 07/2017 | | Joseba Etxeberria | MA |  | CD Basconia | CD Basconia |
Departures
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 02/2018 | | Joseba Etxeberria | MA |  | CD Tenerife | Tenerife |
| 01/2018 | | Mikel Zarrabeitia | FW | | SD Zamudio | SD Zamudio |
| 01/2018 | | De Eguino | DF | | Sestao River | Sestao River |
| 09/2017 | | Aurtenetxe | DF |  | Dundee FC | Dundee FC |
| 08/2017 | | Orbegozo | FW |  | CD Lagun Onak | CD Lagun Onak |
| 07/2017 | | Iñaki Olaortua | DF | | Barakaldo CF | Barakaldo CF |
| 07/2017 | | Adrien Goñi | MF |  | CD Calahorra | CD Calahorra |
| 07/2017 |  | Rubén Alves | DF | | Barakaldo CF | Barakaldo CF |
| 07/2017 | | Baqué | MF | | Athletic Club B | Bilbao B |
| 07/2017 | | Javi Moreno | MF |  | Marbella FC | Marbella |
| 07/2017 |  | Dieng | FW |  | CD Vitoria | CD Vitoria |
| 07/2017 | | Koldo Obieta | FW | | CD Vitoria | CD Vitoria |
| 07/2017 | | Aitor Larrazábal | MA | | Barakaldo CF | Barakaldo CF |