South Africa fly-half Morne Steyn should be fit to face Scotland this weekend.
Steyn lasted just 18 minutes of the Springboks' 24-15 victory over Wales in Cardiff on Saturday before suffering back spasms.
But he has responded well to treatment and the tourists are hopeful he will be fit to play at Murrayfield.
Team doctor Craig Roberts said: "We were monitoring him during the game and he was struggling to kick and run, so we made the call to take him off/
"Clinically it looks like a facet-joint irritation, which usually takes two to three days to settle. It's already looking much better today and our physiotherapists will work hard to sort him out.
"Luckily we've got a long week to get him ready and we're hoping to have him available for selection this weekend. Based on how he's responded so far, it's looking good."
The team to face Scotland will be announced on Thursday. Should Steyn not be available it is likely Pat Lambie will move from full-back to fly-half as his replacement.