Moerat will add to his 11 caps and partner Ruan Nortje in the second row, behind hooker Malcolm Marx and props Ox Nche and Thomas du Toit.
Loose-forward Siya Kolisi will captain the side alongside Pieter-Steph du Toit and number eight Jasper Wiese in the back row.
Sacha Feinberg-Mngomezulu starts at flyhalf, with Morne van den Berg at scrumhalf, and Damian de Allende and Jesse Kriel in the centres.
Ethan Hooker and Kurt-Lee Arendse are on the wing, with Damian Willemse at fullback.
“The vital factors for us will be to be accurate in our execution and to play for the full 80 minutes, especially given the high stakes at the end of these three pool matches,” Springbok coach Rassie Erasmus said.
South Africa face France on November 14 and Ireland on November.
Team: 15-Damian Willemse, 14-Kurt-Lee Arendse, 13-Jesse Kriel, 12-Damian de Allende, 11-Ethan Hooker, 10-Sacha Feinberg-Mngomezulu, 9-Morne van den Berg, 8-Jasper Wiese, 7-Pieter-Steph du Toit, 6-Siya Kolisi (captain), 5-Ruan Nortje, 4-Salmaan Moerat, 3-Thomas du Toit, 2-Malcolm Marx, 1-Ox Nche
Replacements: 16-Jan-Hendrik Wessels, 17-Gerhard Steenekamp, 18-Wilco Louw, 19-Lood de Jager, 20-Cameron Hanekom, 21-Paul de Villiers, 22-Grant Williams, 23-Manie Libbok