According to Springbok team doctor Craig Roberts, Steyn picked up a back spasm during the warm-up before South Africa’s 24-15 victory over Wales at the Millennium Stadium in Cardiff last Saturday.
“We were monitoring him during the game and he was struggling to kick and run, so we made the call to take him off,” Roberts said on Monday.
“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 Springbok team to face Scotland would be announced on Thursday afternoon.
Sunday’s Test kicks off at 5pm SA time.