The South African Test squad will start full training on Wednesday after all 17 players returned negative results after a third round of Covid-19 tests.
South Africa meet Sri Lanka in the first of two world championship Test matches, starting at Centurion on Saturday.
Because of Covid protocols, the players trained in small groups after assembling last Saturday, pending the results of tests on Tuesday.
Cricket South Africa released an updated squad list on Tuesday, omitting two players who were withdrawn from the series after testing positive last week.
Missing from the original group of 19 are left-arm fast bowler Beuran Hendricks and batsman Keegan Petersen. They did not join the rest of the squad after all the players were tested before assembling in a bio-secure environment at a country club near Pretoria. The other players had a second round of tests when they checked in.
Hendricks had a good chance of being in the starting 11. He made his debut in South Africa's most recent Test, against England in January, and took five for 64 in the second innings.
With spearhead Kagiso Rabada unavailable because of injury and long-time stalwart Vernon Philander retired, Hendricks would have been an option alongside Anrich Nortje and Lungi Ngidi in a three-pronged specialist pace attack.
Hendricks' absence could provide an opening for uncapped Glenton Stuurman, who is similar to the retired Philander a persistent, accurate seam bowler.
Petersen was unlikely to have played unless one of the regular top-order batsmen was injured or unavailable.
Revised South African squad: Quinton de Kock (captain), Temba Bavuma, Faf du Plessis, Dean Elgar, Sarel Erwee, Keshav Maharaj, Aiden Markram, Wiaan Mulder, Lungi Ngidi, Anrich Nortje, Dwaine Pretorius, Migael Pretorius, Lutho Sipamla, Glenton Stuurman, Rassie van der Dussen, Raynard van Tonder, Kyle Verreynne.