| Challenger - Bengaluru | 02/07 06:05 | 19 | [206] Arjun Kadhe v Erler, Alexander [350] | 6-3,6-4 | |
| Challenger - Bengaluru | 02/06 10:40 | 14 | Manish Sureshkumar v Erler, Alexander | 2-6,4-6 | |
| Forli 5, Italy, Qualifying | 01/16 12:55 | 14 | [353] Erler, Alexander v Lucas Miedler [290] | 1-6,3-6 | |
| Challenger Maia | 12/14 14:40 | 25 | [342] Erler, Alexander v Fabian Marozsan [376] | 1-6,2-6 | |
| Forli 6, Italy | 12/06 15:25 | 25 | [340] Erler, Alexander v Vitaliy Sachko [255] | 6-3,2-6,2-6 | |
| Forli 6, Italy | 11/28 12:00 | 14 | Erler, Alexander v Valentin Vacherot | 3-6,2-6 | |
| Challenger Manama | 11/23 11:40 | 25 | [463] Haerteis, Johannes v Erler, Alexander [339] | 6-3,6-4 | |
| Challenger Ortisei | 11/07 14:10 | 14 | [325] Erler, Alexander v Cozbinov, Alexander [277] | Retired | |
| Challenger Eckental | 11/02 13:15 | 25 | Henri Squire v Erler, Alexander | 7-6,2-6,7-6 | |
| Challenger Eckental | 11/01 10:00 | 19 | Erler, Alexander v Henri Squire | 4-6,2-6 | |
| Challenger Eckental | 10/31 10:35 | 14 | [327] Erler, Alexander v Dubrivnyy, Artem [472] | 6-1,6-3 | |
| ATP Vienna | 10/23 09:00 | 14 | [328] Erler, Alexander v Gianluca Mager [67] | 7-6,2-6,4-6 | |
| Challenger Sibiu | 09/28 07:00 | 25 | Erler, Alexander v Geoffrey Blancaneaux | Cancelled | |
| Challenger Bucharest | 09/20 11:20 | 25 | [260] Vitaliy Sachko v Erler, Alexander [329] | 6-2,6-2 | |
| Challenger Tulln | 09/06 12:10 | 25 | [327] Erler, Alexander v Lukas Rosol [236] | 4-6,7-5,1-6 | |
| Challenger Como | 08/31 08:00 | 25 | [307] Riccardo Bonadio v Erler, Alexander [327] | 3-6,6-3,6-3 | |
| Challenger Como | 08/30 09:00 | 19 | [319] Baldi, Filippo v Erler, Alexander [327] | 6-7,4-6 | |
| Challenger Como | 08/29 11:45 | 14 | Marcello Serafini v Erler, Alexander | 1-6,6-3,6-7 | |
| Challenger Warsaw | 08/25 12:40 | 25 | [292] Nicolas Kicker v Erler, Alexander [323] | 2-6,7-5,6-3 | |
| Kitzbuhel, Austria | 07/28 14:50 | 26 | [99] Ymer, Mikael v Erler, Alexander [337] | 6-2,6-3 | |
| Kitzbuhel, Austria | 07/27 15:00 | 25 | [337] Erler, Alexander v Carlos Alcaraz [55] | 7-5,1-6,6-2 | |
| Kitzbuhel, Austria | 07/26 08:00 | 25 | Erler, Alexander v Bedene, Aljaz | Cancelled | |
| Challenger Tampere | 07/21 09:00 | 26 | [327] Geoffrey Blancaneaux v Erler, Alexander [339] | 6-3,4-6,6-2 | |
| Challenger Tampere | 07/20 10:30 | 25 | [235] Gastao Elias v Erler, Alexander [339] | 4-6,6-3,5-7 | |
| Challenger Tampere | 07/19 12:25 | 19 | [339] Erler, Alexander v Bogdan Bobrov [439] | 6-4,5-7,1-6 | |
| Challenger Tampere | 07/18 09:45 | 14 | Erler, Alexander v Eero Vasa | 6-2,3-6,6-2 | |
| Challenger Salzburg | 07/06 10:10 | 25 | [317] Alexey Vatutin v Erler, Alexander [334] | 2-6,6-4,6-2 | |
| Challenger Salzburg | 07/05 09:00 | 19 | [400] Vanneste, Jeroen v Erler, Alexander [334] | 4-6,2-6 | |
| Challenger Salzburg | 07/04 09:15 | 14 | [444] Doumbia, Sadio v Erler, Alexander [334] | 6-7,5-7 | |
| ITF M25 Klosters | 06/24 07:00 | 26 | [334] Erler, Alexander v Nicolas Moreno De Alboran [516] | 1-6,5-7 |