Adriaanse replaces Jannie du Plessis, who asked to be withdrawn from the squad because his wife is due to have their third child in early November.
"Jannie and I had a good conversation on Wednesday evening and he still has a burning desire to be part of the Springboks," South Africa coach Allister Coetzee said in a statement.
Carr made his Springboks debut in November 2014 against Italy and has two test caps. Adriaanse has played in four tests and was a member of the 2016 Rugby Championship squad.
The pair are already part of a locally-based Springboks squad who will take on the Barbarians in London at Wembley Stadium on Nov. 5. Having initially been expected to be released after that fixture, they will stay on for the rest of the tour.
South Africa are trying to end a disappointing 2016, which included a record 57-15 home loss to New Zealand earlier this month, on a positive note.
(Reporting by Nick Said, editing by Simon Cambers)
