South Africa have called up uncapped batsman Quinton de Kock as batting cover ahead of the second Test against Australia in Port Elizabeth.
Opening batsman Petersen has a viral infection and a late decision on his availability will be taken before play gets underway.
De Kock was recently awarded a Cricket South Africa (CSA) national contract for the first time following a string of impressive performances in Twenty20 and One-Day International cricket.
Despite hitting three centuries in successive games against India, de Kock was not selected for the Test series that followed or this one against Australia.
The selection panel claimed his omission enabled them to maintain consistency in selection, but in the wake of a humbling 281-run defeat in the opening Test at Centurion Park, he is drafted in with Petersen struggling.
Since making his debut in 2010 against India, where he scored a century, Petersen has made the opening slot alongside Graeme Smith his own, hitting four more centuries in 29 Tests and averaging 37.30.
Although CSA named an unchanged squad for the second Test, which begins in Port Elizabeth tomorrow (20th February), changes to the side are certain.
Ryan McLaren misses out due to concussion and is not available for selection but others may also be left out.
© Cricket World 2014