| 1. Ronde | 18.10.2020 | Arenas de Getxo | - | Athletic Club B | 1:1 | ||||
| 2. Ronde | 25.10.2020 | Athletic Club B | - | Racing Santander | 0:1 | ||||
| 3. Ronde | 01.11.2020 | Club Portugalete | - | Athletic Club B | 2:3 |  |
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| 6. Ronde | 22.11.2020 | SD Leioa | - | Athletic Club B | 1:1 | ||||
| 8. Ronde | 05.12.2020 | CD Laredo | - | Athletic Club B | 2:2 | ||||
| 10. Ronde | 19.12.2020 | Real Sociedad B | - | Athletic Club B | 1:2 | ||||
| 15. Ronde | 06.02.2021 | SD Amorebieta | - | Athletic Club B | 2:3 | |
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| 16. Ronde | 14.02.2021 | CD Alavés B | - | Athletic Club B | 0:2 | ||||
| 19. Ronde | 06.03.2021 | Athletic Club B | - | CD Laredo | 2:1 | ||||
| 20. Ronde | 14.03.2021 | Barakaldo CF | - | Athletic Club B | 3:1 | |
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| 22. Ronde | 28.03.2021 | Real Unión | - | Athletic Club B | 0:1 |
Spanje