South Africa added forwards Ashley Johnson and Ryan Kankowski to a constantly changing squad amid injury and illness concerns ahead their Tri-nations Tests against the Wallabies and All Blacks.
It was the second revision in as many days to the original 24-man group after flank Heinrich Brussow was called up to increase the back-row options for coach Peter de Villiers.
Johnson, who plays for Super Rugby side the Cheetahs, can play flanker or No.8 while the Sharks Kankowski is a specialist No.8.
The call-ups came after utility forward Danie Rossouw suffered gastroenteritis while number eight Pierre Spies is battling to overcome a groin injury and did not train Monday in Durban.
Back-row injuries are a major concern for De Villiers ahead of this weekend's test against the Wallabies in the Indian Ocean City with Schalk Burger, Juan Smith, Willem Alberts and Duane Vermeulen all ruled out of the home leg of the southern hemisphere championship.