Mattia Drudi will sub for Dries Vanthoor at Kyalami this weekend as a result of the Belgian feeling unwell.
Drudi joins an Audi Sport Team WRT entry featuring Charles Weerts and Christopher Haase, who lies joint-second in the Intercontinental GT Challenge Powered by Pirelli drivers' standings ahead of the season finale.
He's two points behind Ferrari's Come Ledogar/Alessandro Pier Guidi and Nicklas Nielsen, who have been split across AF Corse's two 488s this weekend.
Drudi finished fifth alongside Haase and Patric Niederhauser in South Africa last season.
Pre-Qaulifying kicks off Friday's action at 10:35 SAST (GMT +2) ahead of Qualifying and Superpole.