Touch rugby is practically a non-contact sport, but that did not prevent reigning Olympic and world 400 metres champion Wayde van Niekerk sustaining a serious injury.

Van Niekerk will undergo surgery in Colorado after suffering medial and lateral tears of the meniscus and a torn anterior cruciate ligament while playing in a celebrity game ahead of South Africa's Rugby Championship meeting with New Zealand earlier this month.

The 25-year-old is not expected to return to the track until the second half of 2018, ruling him out of the Commonwealth Games in Gold Coast in April.

"I was looking forward to competing in the 100m and 200m events in Gold Coast, and participating at the national championships in March, so this is unfortunate timing," said Van Niekerk in a statement.

"But this is sport and these things happen. I trust that the team I have around me, including the medical professionals, will make this process as smooth as possible.

"I have faith that, God willing, I'll be able to race again later next year. Full recovery is going to be crucial, so I'll be patient, but I will work as hard as I can to get back on the track as soon as possible."