South Africa scrum-half Fourie du Preez will miss Saturday's Test match against Scotland after injuring a quadriceps muscle in training.
Ricky Januarie therefore comes into the XV for the Murrayfield encounter, with his place on the bench taken by utility forward Danie Rossouw.
Du Preez, meanwhile, has dropped out of coach Peter de Villiers' 22 altogether.
The world champions had named an unchanged line-up from Saturday's 20-15 victory against Wales last weekend.
"When you lose the best scrum-half in the world it's certainly going to affect your game, but it's not a train smash," said skipper John Smit.
"We're lucky we've got Ricky, who has 30 or 40 caps as well, so he understands the game.
"He's probably got other strengths as well. He's probably more the guy that will snipe round the edges.
"Ruan [Pienaar, the fly-half] might have to take a bit more pressure from the kicking point of view, but Ricky will take pressure off.
"It's not ideal. We wanted to draw strength from having the same 22 players two weeks in a row - we wanted to improve with the same 22 from the week before."