Wicketkeeper Quinton de Kock made himself unavailable for South Africa's T20 World Cup match against West Indies after refusing to take the knee.
Cricket South Africa (CSA) issued a directive before the match that all players should make the gesture.
It said it will "await a further report from team management before deciding on next steps".
Captain Temba Bavuma said: "As a team we're obviously surprised and taken aback by the news."
He added: "Quinton is an adult. He's a man in his own shoes. We respect his decision. We respect his convictions.
"I know that he'll be standing behind whatever decision that he's taken."
South Africa beat West Indies by eight wickets to claim their first win of the tournament.
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De Kock, who has previously declined to take a knee, said in June: "My reason? I'll keep it to myself. It's my own, personal opinion.
"It's everyone's decision; no-one's forced to do anything, not in life. That's the way I see things."
The CSA statement read: "All players are expected to follow this directive for the remaining games of the World Cup.
"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."
'Why wasn't this planned better?'
West Indies all-rounder Carlos Brathwaite told BBC Radio 5 Live Sports Extra: "I know Quinton de Kock quite well and I have never felt any bad blood or bad vibe from him. We get on very well but I want to know from him what his reason was.
"I'm not an advocate of forcing anyone to do something that they don't want to do. But I also understand where Cricket South Africa is coming from, this is a watershed moment for the Black Lives Matter movement.
"There are a lot of conversations and a lot of education that still has to happen around why you take the knee, what it signifies, but, more importantly for things to change in society, taking a knee has to be a start and not the be all and end all.
"Why wasn't this planned better? Why wasn't there a meeting or a directive before the tournament to let everyone know that this is where Cricket South Africa stands?"
De Kock, 28, stood with his hands behind his back during the show of solidarity during South Africa's limited-overs series against West Indies in July.
CSA said in November that players had three options to show their support for social equality: kneeling, raising a fist or standing to attention.
Some South Africa players - but not all - took the knee before the defeat by Australia in their T20 World Cup opener Saturday, when De Kock scored seven.
South Africa face Sri Lanka in Sharjah on Sunday.
Bavuma said: "We've got a couple of days until our next game, and those days will be tough for the group.
"But the guys will want to know in terms of his decision - they will use that time to find out, to find it out a bit better."
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