South Africa coach Jake White is hoping the four new faces in his tour squad will grasp their opportunities to shine in England and Ireland next month.
White said that injuries were one factor for the changes, but he also wanted to see how some of younger players react without the senior experienced members of the squad.
"It is an opportunity for guys like Albert van den Berg and Johan Muller to take charge of the line-outs," he said.
"When you have Victor (Matfield) there it is all calm and Victor runs the line-outs. For us as a coaching staff it is nice to give some other guys the head role in the set-pieces.
"It is not just a case of resting players, a lot of players have niggling injuries and there is a bigger picture of playing players in the World Cup.
"We saw the impact we had of losing top players this year," White said referring to the loss of Schalk Burger, Bakkies Botha, Ashwin Willemse and Gurthro Steenkamp.
"We have taken the decision to make sure that this doesn't happen again next year."
White also explained the rationale behind the selection of Steyn, who was a surprise in the squad as he has only played a handful of senior games.
"He played full-back, fly-half and centre for the SA Under-19 team as well. I phoned his school, Grey College and they gave me all the facts and figures of him as an athlete.
"He could probably have played anywhere. He is 105kg, and kicks for posts and he is one of those players we can look at going forward," White said.
The convenor of selectors Peter Jooste also announced that five players would join the Boks for their final game - the World XV festival game in Leicester - at the end of the tour.
Winger Jonghikaya Nokwe, scrum-half Bolla Conradie, midfielder De Wet Barry, lock Selborne Boome and flank Wikus van Heerden all will make the trip as White looks to rest some of his players at the end of a tough tour.