His decision comes after the Cricket South Africa (CSA) board announced that all players would be required to take a knee before World Cup games in the United Arab Emirates.
The 28-year-old de Kock did not feature in South Africa’s game against the West Indies on Tuesday.
“This is also the global gesture against racism that has been adopted by sportspeople across sporting codes because they recognise the power of sport to bring people together,” said a statement from CSA.
“After considering all relevant issues, including the freedom of choice of players, the Board had made it clear it was imperative for the team to be seen taking a stand against racism, especially given SA’s history.”
“The Board’s view was that while diversity can and should find expression in many facets of daily lives, this did not apply when it came to taking a stand against racism,” added the CSA statement.
The statement added that the CSA board is awaiting a further report from team management in light of de Kock’s decision.
Before the side’s match against Australia on Saturday, some South African players knelt and raised a fist, while others remained standing with raised fists.
The anti-racism gesture of athletes taking a knee, made famous in 2016 by NFL quarterback Colin Kaepernick, has become an increasingly common sight at sports venues as a show of support for the Black Lives Matter movement.
In the English Premier League, for example, players have been taking a knee before games since the 2019/20 season.
And after Indian cricketers took the knee before their T20 World Cup game against Pakistan on Sunday, some felt the players should have instead done more to highlight issues in India.
India went on to lose its Super 12 clash against Pakistan, whose players put a hand on their hearts while India’s players knelt.
According to India captain Virat Kohli, the teams agreed to “pay their tribute towards the same cause” ahead of the match before deciding which gesture to adopt.
“I believe it’s a good thing that they’re doing it because they weren’t doing it for so long and I cannot fathom why cricketers cannot stand for anti-racism,” Sanjay Jha, a cricket author and former spokesperson for India’s main opposition Congress party, told CNN.
“On the other hand, it also exposes the hypocrisy of the fact that we pontificate on the segregationist issues in Western countries … but when it comes to the way minorities are treated in our country, we are so two-faced.”
CNN’s Esha Mitra and Vedika Sud contributed to reporting.