England's first one-day international against South Africa in Cape Town on Friday was postponed after one of the hosts' players tested positive for coronavirus.
Cricket South Africa (CSA) said a player tested positive on Thursday following the Twenty20 series.
The first ODI of the three-match series, due to begin at 11:00 GMT at Newlands, was postponed at about 10:00.
The rearranged games will now take place on Sunday, Monday and Wednesday.
CSA said it agreed with the England and Wales Cricket Board to postpone the series opener by two days "in the interests of the safety and well-being of both teams, match officials and all involved".
- How did this happen? And could England's tour be called off?
- South Africa v England - what is the rearranged schedule?
England director of men's cricket Ashley Giles said: "Our number one priority is the health and safety of the England team and management group, and the correct decision was made."
Chief medical officer Dr Shuaib Manjra said South Africa will re-test all players and hotel staff on Saturday.
This is the first England match to be postponed because of a positive case since the outbreak of the pandemic.
Two unnamed South Africa players tested positive before the T20 series last month, forcing the cancellation of an intra-squad practice game.
All matches on the tour are being played without fans, with restrictions similar to those at England's home fixtures in the summer and the teams staying in a bio-secure environment at a nearby hotel.
In England the squads stayed in on-site hotels at Emirates Old Trafford and the Ageas Bowl, but no such facilities are available in South Africa.
England managed to complete a full revised home schedule this summer, with no home or opposition players testing positive, although England pace bowler Jofra Archer missed the second West Indies Test in July after breaching bio-secure protocols.
The T20 series, which England won 3-0, finished on Tuesday.
England players 'didn't get off the bus' - reaction
BBC cricket correspondent Jonathan Agnew on BBC Radio 5 Live: "I'm hearing that the England team bus set off from their hotel, which is only half a mile from the ground, and arrived at Newlands just as word was getting out about the situation in the South Africa camp.
"They didn't get off the bus, which simply carried on around the ground and back to the hotel.
"The worry must be that the South Africa player concerned is not alone in testing positive. The South Africans will all be tested again on Friday and surely any positive results would scupper this three-match series."
Former England women's batter Ebony Rainford-Brent: "It's a big shock and frustrating. Thinking about it, it's incredible England got through their whole home summer programme unscathed.
"Will it swirl around the South Africa camp? Testing might reveal more down the line, so let's hope the series isn't too affected."
- Louis Theroux is back: I May Destroy You star Michaela Coel joins for his new series
- Harry Kane exclusive: The England captain talks VAR, fans returning and Justin Bieber