Quinton de Dock on Tuesday opted out of South Africa's Twenty20 World Cup match against the West Indies "for personal reasons" as the country's cricket board ordered players to take the knee.

Skipper Temba Bavuma said the wicketkeeper-batsman, a former national captain, had made himself unavailable due to "personal reasons" in their crucial Super 12 match in Dubai.

The decision raised eyebrows as De Kock had previously refused to take part in the anti-racism gesture that has become a regular feature in most sporting events.

"The Cricket South Africa (CSA) Board on Monday evening unanimously agreed to issue a directive requiring all Proteas players to adopt a consistent and united stance against racism by 'taking the knee' prior to the start of their remaining World Cup matches," said a CSA statement.

"Concerns were raised that the different postures taken by team members in support of the BLM (Black Lives Matter) initiative created an unintended perception of disparity or lack of support for the initiative.

"After considering all relevant issues, including the position of the players, the Board felt that it was imperative for the team to be seen taking a united and consistent stand against racism, especially given SA's history."

De Kock refused to take a knee in South Africa's Test series in the West Indies earlier this year.

Eoin Morgan's England took the knee along with the West Indies on day one of the ongoing World Cup and India and Pakistan followed in their key clash on Sunday.

The South Africans playing in Tuesday's game took the knee before the start of the game.

"A commitment to overcoming racism is the glue that should unite, bind and strengthen us," CSA board chairperson Lawson Naidoo said.

"Race should not be manipulated to amplify our weaknesses. Diversity can and should find expression in many facets of our daily lives, but not when it comes to taking a stand against racism."

The statement further added, "Cricket is the second most watched sport globally and the ICC Men's T20 World Cup, being held in the UAE and Oman, is the ideal platform for the Proteas to highlight the national resolve to heal the divisions of the past."

South Africa assistant coach Enoch Nkwe had resigned in August after apparent disagreements with under-pressure head coach Mark Boucher.

Nkwe's resignation came against a backdrop of widespread criticism of Boucher following revelations made at hearings into racism in South African cricket.

The criticism intensified when black former players alleged they were not made to feel welcome in the national team environment during the period in which Boucher was a prominent member of the team.

Former spin bowler Paul Adams said he was racially abused during fines meetings presided over by Boucher which put the spotlight directly on the current coach.

De Kock opts out as South Africa bowl against West Indies in T20 World Cup

South Africa skipper Temba Bavuma won the toss and elected to field against holders West Indies without wicketkeeper-batsman Quinton de Kock in the Twenty20 World Cup on Tuesday.

The Proteas, who lost their tournament opener to Australia, have brought in Reeza Hendricks in place of De Kock who misses out due to "personal reasons".

"It's been a bit challenging to know what a good score is so we want to have a look," Bavuma said on his team's decision to bowl.

"He (De Kock) has made himself unavailable for personal reasons."

West Indies, who were hammered by England in their first Super 12 match after being dismissed for 55, have made one change with Hayden Walsh replacing Obed McCoy.

"The guys have been upbeat despite what happened a couple of days ago," said skipper Kieron Pollard.

"We have just one forced change; McCoy misses out and Hayden Walsh gets an opportunity.

"He did well in the recent bilateral series and we look forward to his legspin, the art and energy that he brings."

Teams

West Indies: Lendl Simmons, Evin Lewis, Chris Gayle, Shimron Hetmyer, Nicholas Pooran (wk), Kieron Pollard (capt), Andre Russell, Dwayne Bravo, Akeal Hosein, Hayden Walsh, Ravi Rampaul

South Africa: Temba Bavuma (capt), Reeza Hendricks, Rassie van der Dussen, Aiden Markram, Heinrich Klaasen (wk), David Miller, Dwaine Pretorius, Keshav Maharaj, Kagiso Rabada, Anrich Nortje, Tabraiz Shamsi