But his contribution to their campaign is not over.
After returning to Cape Town to have surgery, he rejoined the squad before the final pool game against the United States and is being used by coach Heyneke Meyer as a mentor.
With 109 test caps and a renowned rugby brain, he is offering the side some technical pointers on how to beat a physical Wales side.
"It's going to be a massive challenge, but our forwards are playing very good rugby, they are setting a platform and our set phases are going really well," De Villiers told South Africa’s Eye Witness News.
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The Boks needed to to pressure on the Welsh scrum and dominate the lineouts, he said.
"They do have big backs and they will be running at us and we need to be defensively solid. The defence in the last couple of weeks has been really good, we have only conceded one try in the last three games and that was an intercept."
De Villiers was captain when the Boks were stunned 34-32 by Japan in their tournament opener. Wales will in some ways offer a similar threat, he said.
"They are very similar to Japan in a way they chop you low (in the tackle) and then get onto the ball. At the breakdown we need to be very effective, get leg-drive going in contact and hopefully get momentum from the breakdown."
(Editing by Angus MacSwan)
