Stadium: Pista 4 Round: 25 Ground: Hardcourt outdoor
| Challenger Mallorca | 2021/08/31 08:00 | Zielinski, Jan v Gonzalez, Alejandro | 1-6,2-6 |
| Challenger Mallorca | 2021/08/31 08:00 | Zielinski, Jan v Gonzalez, Alejandro | 1-6,2-6 |
| Challenger Mallorca | 2021/08/30 13:00 | Roelofse, Ruan v Gonzalez, Alejandro | 6-7,2-6 |
| ITF M25 Caslano | 2021/08/28 11:30 | Remy Bertola v Gonzalez, Alejandro | 6-2,6-4 |
| ITF M25 Caslano | 2021/08/27 09:30 | Gonzalez, Alejandro v Mateus Alves | 6-3,3-6,7-6 |
| ITF M25 Caslano | 2021/08/26 08:30 | Gonzalez, Alejandro v Jakub Paul | 6-2,7-5 |
| ITF M25 Caslano | 2021/08/25 13:10 | Gonzalez, Alejandro v Noah Schlagenhauf | 6-4,6-1 |
| ITF M25 Muttenz | 2021/08/20 15:30 | Gonzalez, Alejandro v Jakub Paul | 4-6,1-6 |
| ITF M25 Muttenz | 2021/08/19 07:55 | Gonzalez, Alejandro v Louroi Martinez | 6-3,6-2 |
| Challenger Mallorca | 2021/08/31 08:00 | Zielinski, Jan v Gonzalez, Alejandro | 1-6,2-6 |
| Challenger Mallorca | 2021/08/30 08:00 | Mukund Sasikumar v Zielinski, Jan | 5-7,2-6 |
| Challenger Warsaw | 2021/08/25 10:00 | Zielinski, Jan v Tristan Lamasine | 2-6,2-6 |
| Challenger Warsaw | 2021/08/23 09:00 | Zielinski, Jan v Aldin Setkic | 1-6,6-2,7-5 |
| Challenger Warsaw | 2021/08/22 11:15 | Skander Mansouri v Zielinski, Jan | 7-5,3-6,3-6 |
| Polish National Tour | 2021/07/11 13:00 | Zielinski, Jan v Filip Peliwo | 5-7,2-6 |
| ITF M25 Poznan | 2020/08/26 07:55 | Zielinski, Jan v Vit Kopriva | 4-6,2-6 |
| Polish National Tour | 2020/08/18 07:30 | Pawel Juszczak v Zielinski, Jan | 6-2,6-0 |