[1] Van Velzen won two tournaments on the 2020–21 Big Easy Tour as an amateur,[2][3] before turning professional in April 2021.

[4] He joined the Sunshine Tour and recorded a best finish in his rookie season with a tie for 4th at the Kit Kat Group Pro-Am.

[5] On the 2023–24 Sunshine Tour, he was runner-up at the Investec South African Open Championship, three shots behind winner Dean Burmester.

[6] He also won the Mediclinic Invitational[7] and lost in a playoff to Mikael Lindberg at the Bain's Whisky Cape Town Open.

[10] In his fourth start on the 2025 European Tour, he finished runner-up at the Alfred Dunhill Championship in December 2024, one shot behind Shaun Norris.