Stadium: MTA 05 Round: 62 Ground: Clay
| ITF M25 - Portimao | 2023/03/14 11:00 | Guy Den Heijer v Mikel Martinez | 1-6,2-6 |
| ITF M25 - Portimao | 2023/03/13 15:35 | Guy Den Heijer v Miguel Miguel Pereira Lopes | 6-1,6-3 |
| ITF M25 - Quinta Do Lago | 2023/03/09 17:20 | Jesper De Jong v Guy Den Heijer | 6-3,6-1 |
| ITF M25 - Quinta Do Lago | 2023/03/09 13:30 | Sean Hodkin v Guy Den Heijer | 4-6,4-6 |
| ITF M25 - Quinta Do Lago | 2023/03/08 16:15 | Luis Miguel Saraiva v Guy Den Heijer | 4-6,3-6 |
| ITF M25 - Loule | 2023/02/26 10:00 | Timofey Stepanov v Guy Den Heijer | 6-4,6-2 |
| ITF M25 - Faro | 2023/02/21 10:00 | Francois Musitelli v Guy Den Heijer | 6-7,7-6,12-10 |
| ITF M25 - Faro | 2023/02/20 10:00 | Guy Den Heijer v Ryotaro Matsumura | 6-4,4-6,10-3 |
| ITF M15 - Antalya | 2023/03/27 07:00 | Gheorghe Claudiu Schinteie v Niels Visker | 6-4,5-7,10-6 |
| ITF M15 - Antalya | 2023/03/26 08:00 | Federico Valle v Niels Visker | 3-6,1-6 |
| ITF M25 - Quinta Do Lago | 2023/03/08 16:30 | Niels Visker v Ian Luca Cervantes Tomas | 3-6,4-6 |
| ITF M25 - Quinta Do Lago | 2023/03/08 12:00 | Niels Visker v Francisco Vilaca | 6-0,6-4 |
| ITF M25 - Quinta Do Lago | 2023/03/07 12:30 | Niels Visker v Aditya Katticaren | 6-0,6-0 |
| ITF M25 - Loule | 2023/02/28 10:30 | Guy Den Ouden v Niels Visker | 2-6,7-5,10-2 |
| ITF M25 - Loule | 2023/02/27 12:05 | Maurus Malgiaritta v Niels Visker | 3-6,3-6 |
| ITF M25 - Loule | 2023/02/26 10:00 | Manuel G Pinheiro v Niels Visker | 0-6,4-6 |