| UTR Pro Knoxville | 12/10 16:30 | - | Monday, Johannus v Shunsuki Mitsui | View | |
| UTR Pro Knoxville | 12/09 19:00 | - | Monday, Johannus v Andrew Ena | 6-3,6-2 | |
| UTR Pro Knoxville | 12/07 20:00 | - | Monday, Johannus v Nicolas Kobelt | 6-3,5-2 | |
| UTR Pro Knoxville | 12/06 20:00 | - | Monday, Johannus v Teddy Truwit | 6-2,6-4 | |
| UTR Pro Knoxville | 12/05 20:00 | - | Monday, Johannus v Vincent Rettke | 7-6,6-0 | |
| UTR Pro Knoxville | 12/04 20:00 | - | Monday, Johannus v Sabi Roi | 6-4,6-2 | |
| ITF M25 Columbus | 11/15 20:05 | 25 | [267] Jacob Fearnley v Monday, Johannus [209] | 2-6,6-4,7-6 | |
| Challenger Knoxville | 11/07 18:00 | 25 | [219] Monday, Johannus v Gabriel Debru [322] | 6-4,5-7,3-6 | |
| ITF M15 Las Vegas | 10/19 20:30 | 26 | Monday, Johannus v Martinez, Alex | 6-7,5-7 | |
| ITF M15 Las Vegas | 10/18 19:45 | 25 | [362] Trey Hilderbrand v Monday, Johannus [220] | 2-6,6-7 | |
| Challenger Tiburon | 10/04 18:00 | 26 | [199] Monday, Johannus v Alexander Ritschard [210] | 3-6,7-6,6-7 | |
| Challenger Tiburon | 10/02 21:35 | 25 | [225] Laurent Lokoli v Monday, Johannus [199] | 6-7,2-6 | |
| Istanbul, Turkey | 09/06 10:25 | 26 | [192] Monday, Johannus v Jesper De Jong [141] | 5-7,1-6 | |
| Istanbul, Turkey | 09/04 11:30 | 25 | [192] Monday, Johannus v Kacper Zuk [312] | 4-6,6-1,6-4 | |
| Challenger Mallorca | 08/29 12:00 | 25 | [227] Marco Trungelliti v Monday, Johannus [192] | 6-4,6-4 | |
| ITF M25 Aldershot | 08/18 11:30 | 27 | [466] Arthur Fery v Monday, Johannus [224] | 7-5,6-1 | |
| ITF M25 Aldershot | 08/17 08:55 | 26 | Ewen Lumsden v Monday, Johannus | 4-6,4-6 | |
| ITF M25 Aldershot | 08/15 09:00 | 25 | Alec Beckley v Monday, Johannus | 4-6,1-6 | |
| ITF M25 Roehampton | 08/09 12:30 | 25 | Monday, Johannus v William Jansen | 5-7,2-6 | |
| ITF M25 Roehampton | 08/02 11:00 | 26 | Joshua Goodger v Monday, Johannus | 6-3,7-6 | |
| ITF M25 Roehampton | 08/01 09:00 | 25 | Henry Searle v Monday, Johannus | 6-7,6-3,3-6 | |
| ITF M25 Roehampton | 07/21 09:55 | 28 | [219] Monday, Johannus v Luke Saville [368] | 6-7,6-7 | |
| ITF M25 Roehampton | 07/20 10:00 | 27 | Monday, Johannus v Ryan James Storrie | 6-3,4-6,6-1 | |
| ITF M25 Roehampton | 07/19 10:55 | 26 | Monday, Johannus v Badenhorst, Devin | 7-6,6-4 | |
| ITF M25 Roehampton | 07/18 14:20 | 25 | Monday, Johannus v Murgett, Finn | 6-2,6-3 | |
| ITF - M25 Nottingham | 07/11 14:00 | 25 | Monday, Johannus v Patrick Brady | Retired | |
| Wimbledon, London, Great Britain | 06/28 10:00 | 15 | [106] Radu Albot v Monday, Johannus [271] | 3-6,7-6,6-2 | |
| Wimbledon, London, Great Britain | 06/26 10:00 | 14 | [462] Mili Poljicak v Monday, Johannus [271] | 6-3,6-7,3-6 | |
| Ilkley, Great Britain | 06/19 17:10 | 25 | [138] Raul Brancaccio v Monday, Johannus [268] | 6-3,6-3 | |
| Challenger - Nottingham | 06/11 12:45 | 45 | Monday, Johannus v Zachary Svajda | 2-6,2-6 |