Transfers
Recent player movements in and out of the squad
| Date | Player | From | To | Type |
|---|---|---|---|---|
| 09.01.2019 | C. Ganea | Athletic Club | — | Loan |
| 07.01.2019 | Oier Luengo | Athletic Club | — | Loan |
| 31.08.2018 | Sabin Merino | Athletic Club | Leganes | Loan |
| 30.08.2018 | Andoni Tascón | Athletic Club | — | Loan |
| 08.08.2018 | Kepa | Athletic Club | Chelsea | € 79.5M |
| 03.08.2018 | Óscar Gil | Athletic Club | — | N/A |
| 31.07.2018 | C. Atangana | Athletic Club | — | Loan |
| 31.07.2018 | Urtzi Iriondo | Athletic Club | Union St. Gilloise | N/A |
| 24.07.2018 | Xabier Etxeita | Athletic Club | — | Loan |
| 23.07.2018 | Amorrortu | Athletic Club | — | Loan |
| 21.07.2018 | Dopi | Athletic Club | — | Free |
| 17.07.2018 | Xabi Garai | Athletic Club | — | Loan |
| 16.07.2018 | Jonan Amelibia | Athletic Club | — | N/A |
| 12.07.2018 | Murgoitio | Athletic Club | — | Free |
| 05.07.2018 | Oli Fernández | Athletic Club | — | Free |
| 04.07.2018 | Mikel Vesga | Athletic Club | Leganes | Loan |
| 03.07.2018 | Jon Agirrezabala | Athletic Club | — | Free |
| 02.07.2018 | Capa | — | Athletic Club | € 3M |
| 02.07.2018 | C. Ganea | — | Athletic Club | € 1M |
| 02.07.2018 | Dani García | — | Athletic Club | Free |
| 02.07.2018 | Yuri | Paris Saint Germain | Athletic Club | € 24M |
| 01.07.2018 | Ander Mediavilla | Athletic Club | — | N/A |
| 01.07.2018 | Murgoitio | — | Athletic Club | N/A |
| 01.07.2018 | Josu Juste | — | Athletic Club | N/A |
| 01.07.2018 | Urtzi Urzelai | Athletic Club | — | N/A |
| 01.07.2018 | Oier Luengo | — | Athletic Club | N/A |
| 01.07.2018 | Unai López | Rayo Vallecano | Athletic Club | N/A |
| 01.07.2018 | Álex Remiro | — | Athletic Club | N/A |
| 01.07.2018 | Enric Saborit | Athletic Club | Maccabi Tel Aviv | N/A |
| 23.02.2018 | Ager Aketxe | Athletic Club | — | Free |
| 31.01.2018 | Asier Villalibre | Athletic Club | — | Loan |
| 30.01.2018 | Aymeric Laporte | Athletic Club | Manchester City | € 65M |
| 30.01.2018 | Íñigo Martínez | Real Sociedad | Athletic Club | € 32M |
| 20.01.2018 | Eneko Bóveda Altube | Athletic Club | — | N/A |
| 02.09.2017 | Ander Mediavilla | Athletic Club | Oviedo | N/A |
| 30.08.2017 | Gorka Santamaría | Athletic Club | — | N/A |
| 23.08.2017 | Iker Bilbao | Athletic Club | — | € Free |
| 20.08.2017 | Asier Villalibre | Athletic Club | Valladolid | Loan |
| 09.08.2017 | Jon Agirrezabala | Athletic Club | — | Loan |
| 03.08.2017 | Oier Sarriegi | Athletic Club | — | Free |
| 01.08.2017 | Unai Etxebarría | Athletic Club | — | Loan |
| 01.08.2017 | Unai López | Athletic Club | Rayo Vallecano | Loan |
| 24.07.2017 | Eraso | Athletic Club | Leganes | Free |
| 21.07.2017 | Álex Remiro | Athletic Club | — | Loan |
| 15.07.2017 | Gorka Iturraspe | Athletic Club | — | N/A |
| 12.07.2017 | Olaetxea | Athletic Club | — | N/A |
| 11.07.2017 | Jurgi Oteo | Athletic Club | — | Loan |
| 06.07.2017 | Markel Etxeberría | Athletic Club | — | Loan |
| 04.07.2017 | Izaro Abella | Athletic Club | — | N/A |
| 03.07.2017 | Martín Bengoa | Athletic Club | — | N/A |