Scotland blindside flanker Alasdair Strokosch has been ruled out of Saturday's Test with the Springboks due to a calf injury.
Strokosch's place in the starting XV will be taken by John Barclay, who is promoted from the replacements bench to start at openside flanker.
Captain Kelly Brown will move to blindside, with David Denton remaining at number eight and uncapped Edinburgh back-row Stuart McInally comes onto the bench.
Strokosch's injury is a blow as he performed well against New Zealand, particularly on defence.
It is the third change from the side which began the 51-22 loss to New Zealand last weekend and second in the back row after Ross Rennie dislocated a shoulder in the first half of that clash and was replaced by Denton.
Scotland coach Andy Robinson said although losing Strokosch so close to the Test is a setback he was confident Barcaly will do well.
"We wish 'Stroker' a speedy recovery," he said.
"John is an experienced campaigner, while Stuart was with us on the summer tour and is raring to go."
Scotland team doctor James Robson revealed that Strokosch's injury would not keep him on the sidelines for long.
"Alasdair suffered a minor calf strain in training this week and while we were hopeful it would settle in time we believe his recovery has not been sufficient to warrant risking a partially-fit player," he said.
Scotland (revised): 15 Stuart Hogg, 14 Sean Lamont, 13 Nick De Luca, 12 Matt Scott, 11 Tim Visser, 10 Greig Laidlaw, 9 Mike Blair, 8 David Denton, 7 John Barclay, 6 Kelly Brown, 5 Jim Hamilton, 4 Richie Gray, 3 Euan Murray, 2 Ross Ford, 1 Ryan Grant.
Replacements: 16 Dougie Hall, 17 Kyle Traynor, 18 Geoff Cross, 19 Alastair Kellock, 20 Stuart McInally, 21 Henry Pyrgos, 22 Ruaridh Jackson, 23 Peter Murchie.