The 53-year-old recalled most of the players that sat out last Saturday's 32-14 victory over Italy -- achieved, like the win over France the previous weekend, with the Springboks reduced to 14 men for a large part of the match.
One personnel change to the matchday squad from the one that beat France sees Ruan Nortje promoted from the replacements bench to the starting lineup in place of the suspended lock Lood de Jager, while Kwagga Smith returns to the bench in his place.
The only other change is in the backline, where Canan Moodie switches from centre against Italy to wing to fill the void left by Kurt-Lee Arendse, who returned to South Africa after suffering a concussion last week.
"Ireland have been among the top-ranked teams in the last few years, and they are a force to be reckoned with at home," said Erasmus in a statement on Thursday announcing the team.
"They have a good balance of experienced and exciting young players in their squad, and they pose threats up front and with their talented backs, so it's going to require a massive effort to beat them.
"This group of players have never won a match in Ireland before, so we know how tough it's going to be to win here, and that will certainly motivate us.
"It will take a colossal effort, but we are excited about the challenge, and we know that we have to be razor sharp in all departments to get the desired result."
Saturday's game will be a landmark one for the fearsome looking Leinster lock RG Snyman, who will win his 50th cap if he comes on in what is his 'home city'.
"He's a great player and team man, and had it not been for injuries along the way, he would have probably earned 50 caps a while ago," said Erasmus.
"He deserves this achievement, and it speaks volumes about the quality of the player he is."
Team: 15-Damian Willemse; 14-Canan Moodie, 13-Jesse Kriel, 12-Damian de Allende, 11-Cheslin Kolbe; 10-Sacha Feinberg-Mngomezulu, 9-Cobus Reinach; 8-Jasper Wiese, 7-Pieter-Steph du Toit, 6-Siya Kolisi (capt); 5-Ruan Nortje, 4-Eben Etzebeth; 3-Thomas du Toit, 2-Malcolm Marx, 1-Boan Venter
Replacements: 16-Johan Grobbelaar, 17-Gerhard Steenekamp, 18-Wilco Louw, 19-RG Snyman, 20-Kwagga Smith, 21-Andre Esterhuizen, 22-Grant Williams, 23-Manie Libbok