A squad of 48 players gathered in Johannesburg on Monday morning. Of these, 15 are suffering from a range of injuries or require rehabilitation. The latest injury was to Fourie du Preez, who tore medial collateral ligaments in his knee during a training session with his Japanese club last week.
The other injured players are Heinrich Brüssow (arm), Schalk Burger (groin), Lood de Jager (elbow), Jean de Villiers (knee), Pieter-Steph du Toit (knee), Patrick Lambie (neck), Lionel Mapoe (knee), Cobus Reinach (hand), Jan Serfontein (hip and knee), Frans Steyn (pectoral muscle) and Duane Vermeulen (neck).
Roberts said the injury situation was not ideal at this stage of the season. He added that Du Preez should be out for between four and six weeks.
"Every effort will be made to ensure as many of the injured players get game time before we finalise the squad for the Rugby World Cup," said Roberts.
"Obviously we would've liked to have a squad with fully fit players available, but we have to play the hand we are dealt and will work with all of these players individually over the coming weeks.
"Players will be managed individually and we could send them back to their provinces to get game time, but that will be done in consultation with the unions and only when necessary."
Springbok coach Heyneke Meyer said that it was great to see the excitement and spirit among the players, despite the injury problems.
"I'm very excited to get going - it's been a long few months since our last match, but we've worked incredibly hard behind the scenes and done an unbelievable amount of research and planning," said Meyer.