The list includes 15 of the 29 players who were part of the squad for the away leg of the Castle Tri-Nations Series.
The Springbok squad for the home leg of the Castle Tri-Nations series will be announced on Friday.
“Eight of this group have not played any rugby since the end of the Vodacom Super Rugby competition and have been on rehabilitation programmes with their European clubs or with the Springbok squad,” said Springbok coach Peter de Villiers.
“Our medical team is continuing assessments on the remainder of the players who were unavailable for selection for the away leg. There are still injury concerns around a number of them.”
The eight players who have not appeared since the end of the Super Rugby season are: BJ Botha, Heinrich Brüssow, Elton Jantjies, Zane Kirchner, Francois Louw, Johann Muller, Adriaan Strauss and Coenie Oosthuizen.
De Villiers said the players released back to their provinces and clubs remained in contention for Springbok selection for the Tri-Nations and Rugby World Cup.
Players released are:
Bjorn Basson (Vodacom Blue Bulls)
BJ Botha (Munster, Ireland)
Heinrich Brüssow (Toyota Free State Cheetahs)
Adrian Jacobs (The Sharks)
Elton Jantjies (MTN Lions)
Zane Kirchner (Vodacom Blue Bulls)
Patrick Lambie (The Sharks)
Francois Louw (Bath, England)
Charl McLeod (The Sharks)
Lwazi Mvovo (The Sharks)
Odwa Ndungane (The Sharks)
Wynand Olivier (Vodacom Blue Bulls)
Dean Greyling (Vodacom Blue Bulls)
Alistair Hargreaves (The Sharks)
Ryan Kankowski (The Sharks)
Werner Kruger (Vodacom Blue Bulls)
Ashley Johnson (Toyota Free State Cheetahs)
Johann Muller (Ulster, Northern Ireland)
Coenie Oosthuizen (Toyota Free State Cheetahs)
Chiliboy Ralepelle (Vodacom Blue Bulls)
Deon Stegmann (Vodacom Blue Bulls)
Adriaan Strauss (Toyota Free State Cheetahs)
Flip van der Merwe (Vodacom Blue Bulls)-SA Rugby.net