South Africa's team doctor says England are right to be concerned about the safety of the bio-secure bubble they are in with the Proteas after a member of the home team tested positive for coronavirus.
A three-game one-day international series between the sides was meant to begin at Newlands on Friday but the opener had to be postponed at the last minute after the positive result.
Given the security surrounding the bubble, it remains unknown how the positive result has been returned, but Dr Shuaib Manjra says England's worries are valid.
Dr Manjra said: "Clearly there's a cause for concern and England has expressed a concern. England are questioning their confidence that they have in the bio-secure environment and rightfully so.
"It has been a player who has tested positive in the last week, who contracted the virus in the last week, they have cause for concern and we respect that concern.
"We've met with the English medical teams and planned out a way. We will retest all of our players and hotel staff tomorrow, which is Saturday.
"We'll await the results and plan a course of action. Then on Tuesday before the final ODI on Wednesday, we will test the team again."
Strict security measures mean players cannot leave the bubble unless accompanied by an official, leaving Dr Manjra with work to do to determine the source of the positive test.
"I can categorically state that no player was able to leave the hotel environment, simply by virtue of the fact there's security around and the security will not allow a player to leave unless that player is leaving in an official assigned vehicle with an official driver," he said.
"There's a command centre here led by the colonel from the Claremont police force and they strictly enforce the bio-bubble. They wouldn't allow anyone to leave. I'm basically saying it's impossible to leave this bio-secure environment for any player or official."
A pre-series round of testing was done to screen the squads, who are both staying at the Vineyard Hotel near the Newlands ground, and one Proteas player was found to have the virus.
The decision was then made not to host the match as planned on Friday but the sides still hope to play the three-match series in full, with the first game now set for Sunday in Paarl before returning for matches in Cape Town on Monday and Wednesday.
That plan clearly hinges on a fresh bout of testing and it is highly likely that any further confirmed cases would put the series at risk.
England will remain at their base in Cape Town on Friday and Saturday in the hope that the three-match series can begin on Sunday.
Watch the first match of the series between South Africa and England live on Sky Sports Cricket from 7.30am on Sunday.