READ: Good news on Bok injury front
According to team doctor Craig Roberts, Etzebeth suffered the injury in training on Monday.
“Eben felt some discomfort in his calf at the end of our training session,” said Roberts.
“He was immediately pulled from training and had scans on Tuesday, which revealed a grade 1 strain. He has already started with his rehabilitation and we’re confident that he will be ready for the start of the Rugby World Cup.”
The Springboks open their World Cup campaign against Japan in Brighton on September 19.
Their second Pool B game is on September 26 against Samoa in Birmingham, before Tests against Scotland in Newcastle on October 3 and the USA in London on October 7.
Springbok RWC squad:
Willem Alberts, Schalk Brits, Schalk Burger, Lood de Jager, Bismarck du Plessis, Jannie du Plessis, Pieter-Steph du Toit, Eben Etzebeth, Siya Kolisi, Francois Louw, Frans Malherbe, Victor Matfield (vice-captain), Tendai Mtawarira, Trevor Nyakane, Coenie Oosthuizen, Adriaan Strauss, Duane Vermeulen
Jean de Villiers (captain), Damian de Allende, Fourie du Preez, Bryan Habana, Zane Kirchner, Jesse Kriel, Pat Lambie, Willie le Roux, Lwazi Mvovo, Rudy Paige, Ruan Pienaar, JP Pietersen, Handre Pollard, Morne Steyn