South Africa named uncapped Curwin Bosch, Warrick Gelant and Daniel du Preez in a 34-man squad on Saturday for a Rugby Championship opener against Argentina in Port Elizabeth on August 19.
But coach Allister Coetzee must do without first-choice Springboks skipper Warren Whiteley, who is recovering from a groin injury sustained in a 3-0 June series victory over France.
Abrasive lock Eben Etzebeth got rave reviews after standing in as captain in the final win over the French and is likely to continue in that role.
Bosch, who can perform at flyhalf or fullback, starred for the Sharks in Super Rugby this season, finishing as the second-highest points scorer with 140.
The 20-year-old missed the France series because it clashed with the Under-20 World Cup in Georgia.
Bulls fullback Gelant has recovered from a lengthy injury absence to impress as an attacker from deep positions.
Daniel du Preez, the son of former Springboks scrumhalf Robert, joins brother and fellow loose forward Jean-Luc in the squad for the Test at Nelson Mandela Bay Stadium.
"I always said it must be difficult for a player to force himself into the squad," noted South Africa coach Allister Coetzee.
"So I am really pleased that, through their performances, they have earned selection to the Springbok group."
Only seven Lions were selected with winger Ruan Combrinck a surprise omission having recovered from a serious injury.
"The next six contests will be completely different to what we faced against France in June," warned Coetzee.
"We will have to work even harder to meet these tough challenges against the Pumas, Wallabies and All Blacks.
"Thorough preparations will once again be crucial to our Rugby Championship campaign."
Pieter-Steph du Toit (all Western Stormers)
Daniel du Preez
Jean-Luc du Preez
Chiliboy Ralepelle (all Sharks)
Lood de Jager
Trevor Nyakane (all Bulls)
Franco Mostert (all Lions),
Oupa Mohoje (both Cheetahs)
Jan Serfontein (all Bulls)
Courtnall Skosan (all Lions)
Damian de Allende
Dillyn Leyds (both Stormers)
Francois Venter (both Cheetahs)
Curwin Bosch (Sharks)
Francois Hougaard (Worcester/ENG)