| Spain Int XD | 2021/06/18 07:45 | Mueller/Stern v De Wit/Van Wijlick | W | 2-0 |
| Spain Int XD | 2021/06/17 11:40 | Mueller/Stern v Magee J / Boyle S | W | 2-1 |
| Open de Pologne - Doubles Mixtes | 2021/03/28 08:00 | Choong/Toh v Mueller/Stern | L | 2-0 |
| Open de Pologne - Doubles Mixtes | 2021/03/27 16:00 | Mueller/Stern v Kargaev R / Vorobeva V | W | 2-1 |
| Open de Pologne - Doubles Mixtes | 2021/03/27 08:20 | Z-Bexell / Sjoo v Mueller/Stern | W | 0-2 |
| Open de Pologne - Doubles Mixtes | 2021/03/26 14:40 | Mueller/Stern v Szerecz/Gonda | W | 2-0 |
| Open de Pologne - Doubles Mixtes | 2021/03/26 08:20 | Mueller/Stern v Holub/Basova | W | 2-0 |
| Spain Int XD | 2021/06/18 07:45 | Leal/Lopez v Birker P / Hochmeir K | W | 0-2 |
| Austrian Open - Doubles Mixtes | 2021/05/28 11:00 | Choong/Toh v Birker P / Hochmeir K | L | 2-1 |
| Slovenia Int. XD | 2021/05/21 10:00 | Birker P / Hochmeir K v Knudsen/Norrman | L | 0-2 |
| Slovenia Int. XD | 2021/05/21 08:00 | Birker P / Hochmeir K v Doder/Loncar | W | 2-1 |
| Slovenia Int. XD | 2021/05/20 08:00 | Birker P / Hochmeir K v Wassink/Laurens | W | 2-0 |
| Portuguese Int. XD | 2021/05/07 14:00 | Birker P / Hochmeir K v Stoffersen/Fuglsang | L | 0-2 |
| Championnat d'Europe - Doubles Mixtes | 2021/04/28 08:00 | Sonmez / Erdem v Birker P / Hochmeir K | L | 2-1 |
| Orléans Masters - Doubles Mixtes | 2021/03/25 16:45 | van Nieuwkerke J / Jaques L v Birker P / Hochmeir K | L | 2-0 |