Cape Town – Plenty of collective firepower on paper … but an acid test for a significantly reworked loose trio.

Those are key hallmarks of the Springbok team named by head coach Rassie Erasmus on Thursday for Saturday’s Rugby Championship opener against Argentina at Kings Park (17:05 kick-off).

The substantial sacrifice for this tournament of Duane Vermeulen, the powerhouse No 8 who was so influential in June’s 2-1 series triumph over England, is comfortingly offset by the return to the starting line-up of physical, enforcer-type figures like Malcolm Marx and Eben Etzebeth from injury.

Similarly, in being deprived of the 42-cap Vermeulen, there is ample compensation in experience terms through Bath-based Francois Louw (57 Test appearances), albeit in a different berth to him, returning to the loosie alliance.

That is the area where the Boks will be under special scrutiny against the Pumas, given the widespread way in which Erasmus – remember, once a world-class loose forward himself, so not acting without great acumen or confidence – has remoulded his plans, now sans Vermeulen’s grunt.

No single player stays in his same role from the trio who did duty, and to admirable standards, in the last two Tests of the England series (Bloemfontein and Cape Town): captain Siya Kolisi, Pieter-Steph du Toit, at seven, and Vermeulen.

Kolisi, of course, is the only one keeping his place in the latest loose trio but there is a notable shift for the Stormers man: back from the open-side role to the No 7 duty.

It may not have been an easy step for coach Erasmus to take, mindful that there was a period in his Test career, now stretching back to 2013, when Kolisi operated at blind-side but, while always being a firm tackler and willing ball-carrier, didn’t always give quite as much broad “go-forward” as you would wish of the player in that position.

A spot sometimes occupied by forwards who have the tonnage to double as imposing locks, the Zwide-born competitor tips the scales at a relatively modest 103kg and isn’t the tallest No 7 in the world, either.

A personal view is that Kolisi’s gradual education in the fetcher berth should have been allowed to continue, even as it remains apparent he is not the most natural of pilferers.

Truth be told, if there was a role somewhere directly between six and seven for flankers – say a six-and-a-half jersey? – then Kolisi would tick the box wonderfully.

Instead there is renewed pressure on him to readjust swiftly to the blind-side responsibility, and knowing full well that his No 8, the skilful, roaming former national skipper Warren Whiteley, is also no Vermeulen in the pure bulldozing stakes.

That is where Louw, now to play his first Test since the 35-6 victory over Italy at Padova in November last year, will come in useful for his own, not inconsiderable tale of the tape – 114kg and 1.90m, making him the most physically imposing of the Bok starting loosies this weekend.

Although officially stationed at six and expected to be a significant nuisance over the ball against the Pumas, he is not unlike Kolisi in being adaptable between the two flank roles (not to mention increasingly comfortable at No 8 if required, too).

Louw is a rugged ball-carrier when the opportunity arises, and bear in mind that he was playing full-time on the blindside toward the climax of his final season with the Stormers in 2010 before his switch to the English Premiership.

In the Super Rugby final that year, which Louw started in, Schalk Burger was the No 6 and Vermeulen wearing the eighth-man jersey in the defeat to compatriots the Bulls in Soweto.

So perhaps the cross-over abilities of both Bok flankers will come in useful this Saturday, the sum of their parts adding up to one satisfying “whole” rather than the Boks looking disjointed or unbalanced in the loose-forward scrap.

Nevertheless, there is a case for saying that Du Toit is unfortunate to lose his blindside flank place – the loose combo sacrifices his 120kg ballast and 2m lineout attributes – after operating there in six of his last seven starts for South Africa and getting more and more accomplished.

But you also won’t hear too many complaints from the blond dynamo, as he stays in the team by restoring his second-row partnership (lock is probably still his preferred position) with franchise-mate Etzebeth.

The Boks will miss Vermeulen’s substantial lineout prowess at the back, but Whiteley is a spring-heeled factor in that area so they should not be caught too literally “short” against the Argentineans there …

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