| Internazionali d'Ungheria | 2019/10/31 12:40 | Raul Must v Joel Koenig | L | 2-0 |
| Internazionali d'Ungheria - Qual. | 2019/10/30 17:30 | Joel Koenig v Dimitar Yanakiev | W | 2-0 |
| Internazionali del Messico | 2019/09/19 17:30 | Joel Koenig v Bernardo Atilano | L | 0-2 |
| Internazionali del Belgio - Qual. | 2019/09/11 15:15 | Joel Koenig v B.M. Rahul Bharadwaj | L | 0-2 |
| Internazionali di Bielorussia | 2019/08/31 09:40 | Joel Koenig v Kartikey Gulshan Kumar | L | 0-2 |
| Hellas Open | 2019/08/09 06:30 | Adrian Dziolko v Joel Koenig | L | 2-0 |
| Peru Future Series | 2019/05/10 21:00 | Joel Koenig v Daniel La Torre Regal | L | 0-2 |
| Internazionali d'Olanda - Qual. | 2019/04/11 14:20 | Bruno Carvalho v Joel Koenig | L | 2-1 |