Springbok coach Heyneke Meyer admits that a lack of lock options has prompted to him field an unconventional second-row combination for Saturday's clash with Samoa at Loftus Versfeld.
Flip van der Merwe starts - ahead of Juandre Kruger - alongside Eben Etzebeth in a second row featuring two number 4 locks but no recognised line-out leader.
South Africa do have another specialist number 5 in their squad in the form of Franco van der Merwe and Meyer has stated previously that he believes Etzebeth could one day fill the role.
But Meyer wants to explore his options ahead of the Rugby Championship and given Flip van der Merwe's good form and experience, he opted to give the Bulls lock a trial run in the number five jersey.
"I want to make it very clear that Juandre Kruger played one of his best test matches on Saturday. I want to see if Eben and Flip can play together," said Meyer.
"At this stage we're very thin at number 5 lock and I don't want to go into the Rugby Championship without having tried and tested that. Juandre has been playing great rugby but I'd like to test the combination. They have to prove they can play together.
"Eben is a guy we believe can play at five. He has only played there once in a previous game. We believe at this stage that Flip is more experienced and it was a decision that came after long and hard thought.
"We believe Flip's best position is number 4 and we see him going that way going forward. But it takes time to develop in a number 5 jumper and with youngsters like Pieter-Steph (du Toit) coming through, it will take time. I would also love to give Eben Etzebeth an opportunity but we felt Flip is more experienced," Meyer explained.
"I think Flip has been playing well and we wanted to give him a start, and we also still have the insurance of Juandre on the bench and we can always bring him on if we need to."
The breakdown areas had been a talking point this week after the match against Scotland and it was hoped that Francois Louw's return as a specialist openside flanker would help remedy this area of play.
Meyer said the inclusion of Louw and Willem Alberts was not a reflection of what he thought of Marcell Coetzee and Siya Kolisi's performances against Scotland.
"Francois Louw better understands how the Northern Hemisphere referees officiate the breakdowns and he is a recognised openside flanker," said Meyer.
"Francois and Willem were the loose forwards on the year-end tour with Duane Vermeulen and they really did well.
"Francois was always going to be back this week and Willem has been our first-choice ball carrier, so it's been good to have them back on the training field.
"Because Willem is returning from an injury, we decided to start with him. Siya played very well last weekend and it is great to have someone of his versatility on the bench. We saw last week how valuable it is to have replacement players who can make a real impact late in the match.
"I'm happy that we've been able to keep some form of continuity during these tests, especially in the backline, where a number of exciting new players have come in and put up their hands during Super Rugby and in the last two weeks."
Meyer said the match against Samoa will be a proper test for his squad.
"They have a strong squad and have benefited from having their best players compete in Super Rugby and at the top club level in Europe, but our focus is on putting in an improved performance from last week," said Meyer.
Hooker Adriaan Strauss will take over captaincy on Saturday if incumbent Jean de Villiers does not recover from a shoulder injury in time.
De Villiers was, nevertheless, included in the starting XV Springbok coach Meyer announced on Wednesday for the final of the four-nation tournament.
The influential leader will be given until Friday to recover from the sternum injury he sustained in their match against Scotland in Nelspruit last weekend.
"There has been good news, he had a scan on Tuesday and there is nothing broken and he is much better today but it is still a 50-50," Meyer said.
"We will wait until Friday before we make a decision... he is a warrior and hopefully he will be fit. I think we need him because it is going to be a really tough game.
"If Jean is not ready, Adriaan will captain the side. I've known him since he was a youngster and I thought he would be a great leader going forward and he has shown with the Cheetahs that he is a brilliant leader."