JP Pietersen and Willie le Roux have been left out of South Africa's training squad for the Rugby Championship, while Bryan Habana has been recalled.
The duo have over 100 combined caps for the Springboks, with Pietersen helping South Africa to Rugby World Cup glory in 2007.
Wing Pietersen scored what proved to be the crucial try in the decisive third Test of their series with Ireland in June, but both he and full-back Le Roux have been omitted by coach Allister Coetzee.
"JP and I recently held discussions and I have decided to give him a much-needed break because he has played a lot of rugby the past three years," Coetzee said.
"Although he has joined English club Leicester, he will still be available for the Springboks. The same applies to Willie, who has just signed with Wasps."
Habana did not feature in the series win over Ireland and missed out on a place in South Africa's rugby sevens squad for the Olympic Games.
But the wing, who has 117 caps for South Africa, joins Oupa Mohoje, Vincent Koch, Juan de Jongh, Francois Hougaard and Johan Goosen in being recalled for the four-team tournament.
Uncapped hooker Malcolm Marx is also included having been part of the Lions team beaten by Hurricanes in the Super Rugby final on Saturday.
Not considered for selection are the injured Frans Malherbe, Coenie Oosthuizen, Jan Serfontein, Pat Lambie, Handre Pollard, Cobus Reinach and Siya Kolisi.
South Africa begin their Rugby Championship campaign against Argentina in Nelspruit on August 20.
Squad in full: Ruan Combrinck, Damian de Allende, Lood de Jager, Juan de Jongh, Faf de Klerk, Pieter-Steph du Toit, Eben Etzebeth, Johan Goosen, Bryan Habana, Francois Hougaard, Elton Jantjies, Steven Kitshoff, Vincent Koch, Jaco Kriel, Jesse Kriel, Francois Louw, Lionel Mapoe, Malcolm Marx, Bongi Mbonambi, Teboho Mohoje, Franco Mostert, Tendai Mtawarira, Lwazi Mvovo, Sikhumbuzo Notshe, Trevor Nyakane, Rudy Paige, Julian Redelinghuys, Morne Steyn, Adriaan Strauss (captain), Duane Vermeulen, Warren Whiteley.