Rookie Grant Williams can take the gap against Argentina

This week, much focus has been directed at the periphery, where the Springboks' aerial elasticity is perceived to be lacking. However, it is in and around the heavy traffic where Grant Williams can announce himself as a compelling force at Test level against Argentina on Saturday (5.05pm).

The teams are likely to kick off this year's closing Rugby Championship Test at Johannesburg's Ellis Park in the knowledge the title is already decided, but for the individuals involved, the stakes cannot be higher.

Squads for the Rugby World Cup (RWC) in France are being finalised and scrumhalf Williams, who gets his first crack in the starting team, can cement his place with an authoritative performance from the get-go.

That will be manna for the Boks.

If they are to improve on their disappointing loss against the All Blacks in Auckland earlier this month, they had better vacate the starting blocks with more conviction, and in Williams, they have a dynamo who can get the wheels turning early.

His ability to keep the fringe defence engaged with breakneck speed off the mark makes him a player of immense value. His top-end speed too causes heartache and heartbreak for aspiring cover defences. He is a reveller in wide open spaces, as he is in tight confines.

His halfback partnership with Manie Libbok, who is also yet to shake the rookie tag, will be one of the eagerly observed subplots at Ellis Park.

Libbok's trusty boot makes him near indispensable within a RWC context, but another reassuring performance off the tee can only advance his candidacy.

It is out wide though where Bok fans are hoping the vertically challenged Cheslin Kolbe and Kurt-Lee Arendse can rise to the occasion against lanky opponents.

Los Pumas have surprised by omitting experienced fullback Emiliano Boffelli, but in Juan Imhoff they have another bean pole who can take command around the tramlines.

Like the Boks, Argentina coach Michael Cheika has to test talent and combinations before he names his RWC squad.

Though Imhoff juts 1.85m out of his socks, Kolbe has proven himself a more than capable adversary when required to rise against a taller opponent.

Up front, the Boks can expect feisty opposition. Los Pumas will have their tails up after their win in Sydney over the Wallabies. They are the team that will run out at Ellis Park with momentum, but those reinvigorating properties have perhaps been offset by a taxing travel schedule over the past few weeks.

Their travels in the Rugby Championship have seen them leave their Buenos Aires base for touchdown in Mendoza, Santiago, Sydney, back to Buenos Aires, Sao Paulo and Johannesburg.

On top of that, they will on Saturday have to come to grips with Johannesburg's thin, dry air, which may well help the Bok bench come into their own.

A fast start and lung-busting finish with Kwagga Smith leading the charge may well feature prominently in the Boks' match-day playbook.

Teams

South Africa: Willie le Roux, Cheslin Kolbe, Jesse Kriel, Damian de Allende, Kurt-Lee Arendse, Manie Libbok, Grant Williams, Duane Vermeulen, Pieter-Steph du Toit, Marco van Staden, Marvin Orie, Eben Etzebeth, Frans Malherbe, Malcolm Marx, Steven Kitshoff.

Substitutes: Bongi Mbonambi, Trevor Nyakane, Vincent Koch, Kwagga Smith, RG Snyman; Faf de Klerk, Lukhanyo Am, Damian Willemse.

Argentina: Juan Cruz Mallia; Mateo Carreras, Lucio Cinti, Santiago Chocobares, Juan Imhoff; Santiago Carreras, Lautaro Bazan Velez; Juan Martin Gonzalez, Santiago Gromdona, Pablo Matera; Tomas Lavanini, Lucas Paulos; Francisco Gomez Kodela, Julian Montoya (captain), Thomas Gallo. Substitutes: Igancio Ruiz, Nahuel Tetaz Chaparro, Joel Sclavi, Pedro Rubiolo, Facundo Isa; Gonzalo Bertranou, Tomas Albornoz, Matias Moroni.

Referee: Andrew Brace (Ireland) Assistant referees: Nika Amashukeli (Georgia) & Chris Busby (Ireland) TMO: Joy Neville (Ireland)