Wales fullback Liam Williams' Rugby World Cup is over after he failed to overcome an ankle injury.
The 28-year-old who has won 62 caps and started all of Wales's World Cup games except one, has been replaced by Leigh Halfpenny in the line-up to face South Africa.
Coach Warren Gatland also announced on Friday the return of fit-again Jonathan Davies at the centre.
Davies missed the 20-19 win over France in the quarter-finals because of a knee injury. He replaces Owen Watkin, who drops to the bench.
Ross Moriarty is selected at No.8 following the tournament-ending hamstring injury sustained by Josh Navidi against France.
The Springboks also suffered a big blow ahead of the semi-final in Yokohama when winger Cheslin Kolbe was ruled out with injury.
The winner of Sunday's clash will meet either England or New Zealand in the November 2 World Cup final.
Wales team: Leigh Halfpenny, George North, Jonathan Davies, Hadleigh Parkes, Josh Adams, Dan Biggar, Gareth Davies; Ross Moriarty, Justin Tipuric, Aaron Wainwright, Alun Wyn Jones, Jake Ball, Tomas Francis, Wyn Jones.
Reserves: Elliot Dee, Rhys Carre, Dillon Lewis, Adam Beard, Aaron Shingler, Tomos Williams, Rhys Patchell, Owen Watkin.