Stadium: Court 8 Round: 25 Ground: Clay
| ITF M25 Trier | 2021/08/26 09:30 | Constantin Schmitz v Ryan Nijboer | 4-6,2-6 |
| ITF M25 Trier | 2021/08/25 11:40 | Mats Rosenkranz v Constantin Schmitz | 1-6,1-6 |
| ITF M15 Oldenzaal | 2021/08/19 12:35 | Constantin Schmitz v Luke Johnson | 7-5,0-6,3-6 |
| ITF M15 Oldenzaal | 2021/08/18 14:10 | Constantin Schmitz v Zachary Eisinga | 6-3,7-6 |
| ITF M25 Wetzlar | 2021/08/06 15:55 | Constantin Schmitz v Peter Heller | 3-6,7-5,1-6 |
| ITF M25 Wetzlar | 2021/08/05 13:55 | Dayne Kelly v Constantin Schmitz | 2-6,1-6 |
| ITF M25 Wetzlar | 2021/08/04 12:30 | Constantin Schmitz v Jannik Rother | 6-2,6-0 |
| ITF M15 Troisdorf | 2021/05/12 09:00 | Constantin Schmitz v Tom Kocevar-Desman | 6-4,4-6,3-6 |
| ITF M25 Trier | 2021/08/27 12:00 | Marvin Moeller v Mick Veldheer | 6-3,6-3 |
| ITF M25 Trier | 2021/08/26 09:30 | Aliaksandr Bulitski v Mick Veldheer | 3-6,3-6 |
| ITF M25 Trier | 2021/08/24 10:00 | Matthew Romios v Mick Veldheer | 1-6,0-6 |
| ITF M25 Frankfurt nad Mohanem | 2021/08/12 09:00 | Mick Veldheer v Oriol Roca Batalla | 4-6,6-2,4-6 |
| ITF M15 Frederiksberg | 2021/08/06 12:40 | Mick Veldheer v August Holmgren | 4-6,4-6 |
| ITF M15 Frederiksberg | 2021/08/05 10:00 | Mick Veldheer v Palaphoom Kovapitukted | 0-6,6-3,6-3 |
| ITF M15 Frederiksberg | 2021/08/04 11:05 | Mick Veldheer v Philip Hjorth | 6-3,6-3 |
| ITF M15 Vejle | 2021/07/29 16:30 | Guy Den Ouden v Mick Veldheer | 6-4,6-0 |