Michael Clarke hurts hamstring again
Clarke was dismissed for 11 in the series opener in Perth, caught behind by Quinton De Kock after gloving a Dale Steyn bouncer.
But his hamstring troubles struck again during his innings, and he has been ruled out of the remainder of the clash.
Cricket Australia doctor Peter Brukner confirmed the injury, with Clarke to have scans on Saturday.
"Michael Clarke has re-injured his hamstring and will take no further part in today's match," Brukner was quoted as saying by the Cricket Australia website.
"Clarke is currently being assessed and will have a scan tomorrow. George Bailey will step up as captain."