South Africa expect pace bowler Vernon Philander to be fit for the second Test against Sri Lanka, which begins at Kingsmead, Durban on Boxing Day.
Philander injured his left knee in the nets on Saturday.
Team manager Mohammed Moosajee said: "The injury was classified as a mild strain. Philander will be treated with ice, compression and more physiotherapy and will have his knee strapped."
However, Philander's likely stand-in Lonwabo Tsotsobe has a muscle strain.
So if the pair are both ruled out, the Proteas will hand a debut to uncapped seamer Marchant de Lange.
Sri Lanka, who lost the first Test by an innings, have still not won a Test match since legendary spinner Muttiah Muralitharan's retirement from the five-day game in July 2010.
"We haven't been playing good cricket here of late," admitted vice-captain AB de Villiers.
Meanwhile, Sri Lanka captain Tillakaratne Dilshan has hinted that they may hand a debut to wicketkeeper/batsman Dinesh Chandimal, who has played in 17 one-day internationals but is yet to feature in a Test.
Dilshan said: "We have discussed giving him a Test debut and he can gain some valuable experience by playing against South Africa's attack.
"Personally I think he is good for the team and he can be groomed for the future."
South Africa (from): Graeme Smith (capt), Jacques Rudolph, Alviro Petersen, Hashim Amla, Jacques Kallis, AB de Villiers, Ashwell Prince, Mark Boucher (wk), Vernon Philander, Dale Steyn, Morne Morkel, Imran Tahir, Lonwabo Tsotsobe, Marchant de Lange.
Sri Lanka (from): Tillakaratne Dilshan (capt), Tharanga Paranavitana, Lahiru Thirimanne, Kumar Sangakkara, Mahela Jayawardene, Thilan Samaraweera, Kaushal Silva (wk), Dinesh Chandimal (wk), Angelo Mathews, Thisara Perera, Rangana Herath, Chanaka Welegedara, Dilhara Fernando, Ajantha Mendis, Dimuth Karunaratne, Dhammika Prasad, Kanishka Alvitigala.