| ITF M15 Antalya | 03/12 10:30 | 62 | Zielinski, Marcel v 피오렌티니, 안드레아 | 1-6,2-6 | |
| ITF M15 Antalya | 03/09 07:00 | 26 | Cuenin, Sean v Zielinski, Marcel | 6-3,6-0 | |
| ITF M15 Antalya | 03/08 11:30 | 25 | Zielinski, Marcel v 카와카미, 림페이 | 6-3,1-6,6-4 | |
| ITF M15 Antalya | 03/07 07:00 | 19 | Zielinski, Marcel v 포사티, 알베르토 | 3-6,7-6,10-5 | |
| ITF M15 Antalya | 03/06 07:30 | 62 | Zielinski, Marcel v Stepan Mruzek | 6-1,6-1 | |
| ITF M15 Antalya | 03/05 06:30 | 62 | Zielinski, Marcel v Wunder, Markus | 6-4,6-2 | |
| ITF M25 Antalya | 02/02 08:55 | 26 | Zielinski, Marcel v 바레나, 알렉스 | 7-6,2-6,4-6 | |
| ITF M25 Antalya | 02/01 10:30 | 25 | Aleksandr Lobanov v Zielinski, Marcel | 4-6,0-6 | |
| ITF M25 Antalya | 01/31 08:50 | 62 | Zielinski, Marcel v 보지노비치, 라자르 | 6-1,6-1 | |
| ITF M25 Antalya | 01/30 11:45 | 62 | Zielinski, Marcel v Jannik Maute | 6-4,6-1 | |
| ITF M15 Antalya | 01/27 07:00 | 27 | 바레나, 알렉스 v Zielinski, Marcel | 6-4,6-3 | |
| ITF M15 Antalya | 01/26 06:30 | 26 | 마르코브스키, 오브레드 v Zielinski, Marcel | 0-6,1-6 | |
| ITF M15 Antalya | 01/24 11:35 | 25 | Zielinski, Marcel v 팔로시, 스테판 | 4-6,6-4,6-4 | |
| German Championship | 12/09 14:00 | - | Zielinski, Marcel v Rehberg, Max Hans | 3-6,2-6 | |
| German Championship | 12/08 14:00 | - | Zielinski, Marcel v Lasse Portner | 6-2,2-6,6-3 | |
| ITF M15 Heraklion | 11/08 07:30 | 62 | 시니아코브, 다니엘 v Zielinski, Marcel | 6-1,6-2 | |
| ITF M15 Heraklion | 11/07 08:00 | 62 | D'Agostino, Stefano v Zielinski, Marcel | 3-6,6-3,4-10 | |
| ITF M15 Heraklion | 11/06 12:00 | 62 | Fabian Hansch Mauritzson v Zielinski, Marcel | 1-6,0-6 | |
| ITF M15 Heraklion | 11/03 11:35 | 26 | 피에트리, 벤자민 v Zielinski, Marcel | 6-1,6-3 | |
| ITF M15 Heraklion | 11/02 11:50 | 25 | Zielinski, Marcel v Kielan, Szymon | 6-4,2-6,7-5 | |
| ITF M15 Heraklion | 11/01 07:30 | 62 | Zielinski, Marcel v Benjamin Kreynes | 6-2,6-2 | |
| ITF M15 Heraklion | 10/30 07:00 | 62 | Zielinski, Marcel v Rodriguez, Damian | 6-2,6-7,10-7 | |
| ITF M15 Lambermont | 08/27 11:00 | 28 | Slump, Stijn v Zielinski, Marcel | 7-6,6-3 | |
| ITF M15 Lambermont | 08/26 13:40 | 27 | Gilles Arnaud Bailly v Zielinski, Marcel | Retired | |
| ITF M15 Lambermont | 08/25 11:20 | 26 | Zielinski, Marcel v 프리버그, 칼 | 6-7,6-4,6-3 | |
| ITF M15 Lambermont | 08/24 10:30 | 25 | Giammarco Gandolfi v Zielinski, Marcel | 2-6,4-6 | |
| ITF M15 Lambermont | 08/22 08:00 | 44 | Zielinski, Marcel v Jesse De Jager | 6-4,7-6 | |
| ITF M15 Lambermont | 08/22 08:00 | 44 | Zielinski, Marcel v Tommaso Vola | 6-2,6-4 | |
| ITF M15 Eindhoven | 08/18 11:00 | 26 | 피칠러, 디비드 v Zielinski, Marcel | 6-4,6-1 | |
| ITF M15 Eindhoven | 08/16 12:05 | 25 | Slump, Stijn v Zielinski, Marcel | 6-7,4-6 |