South Africa pace bowler Dale Steyn is doubtful for the second Test against England because of a shoulder injury.
Steyn, the world's top-ranked bowler, was unable to bowl on day four of the first Test against England because of a spasm in his right shoulder.
The 32-year-old had scans on Tuesday but they showed no signs of a muscle tear and he will undergo further tests before the second match on 2 January.
South Africa are battling to save the first Test in Durban.
Steyn had only just returned to the Proteas side after missing the majority of their tour of India with a groin injury.
He slumped over holding his bowling arm early in England's second innings and left the field for treatment.
The right-arm paceman returned later and tried to bowl, but pulled up injured again
South Africa have also been disrupted by speculation about the future of star batsman AB de Villiers.
The 31-year-old, who is also keeping wicket during this Test, said on Monday that he was looking to ease his workload amid rumours he is considering retiring.
"There are a lot of rumours flying around I hear, but for the last two to three years the only talk I've been doing is to keep myself fresh and to have a bit of rest here and there," said De Villiers, who is ranked the number three Test batsman in the world.
"It's always been the most important thing for me to enjoy my cricket. It's just important to look at the schedule and for me maybe not to play all kinds of cricket.
"That's the only thing that I've been talking about. To keep myself fresh and to keep enjoying the game. I love representing my country and nothing has changed."