J.J. HarmsePretoria - Peter de Villiers will show his hand on Saturday when he announces a Springbok squad for the Tri-Nations, but the influence of technical advisor Rassie Erasmus is already visible.Rumours from Cape Town, where the preliminary World Cup squad convened on Tuesday and will stay until Friday, are that the Springbok coach has decided to rope in Stormers defence coach Jacques Nienaber. That may be directly down to the influence of Erasmus.Erasmus appointed Nienaber in the role at the Stormers, after which the Cape side became the stingiest in Super Rugby as far as conceding tries was concerned.The Stormers conceded 18 tries in 17 games, while the Springboks leaked 35 tries in last year's 14 Tests. What is really concerning about the Bok stat is that the All Blacks crossed their line 11 times in three Tests and the Wallabies 11 times in four Tests.Even Wales, who will be the Boks' first opponents at the World Cup, scored six tries in two Tests against the Boks (against the five of the Boks).Nienaber's apparent availability (the official announcement is expected on Friday) is definitely good news for De Villiers, who already tried to rope him in last season only for Western Province to scupper the plans.Erasmus, of course, is director of coaching at WP now and has enough clout to be able to get Nienaber involved.De Villiers kindly answered some questions from Sport24 via spokesperson Andy Colquhoun. However, the one that was not answered was how quickly Erasmus's role will be visible on the field. The answer is nevertheless immediately.De Villiers saw the glass half full rather than half empty after the Crusaders ensured that no South African team will be involved in the final week of Super Rugby."Any coach looks for additional time to work with his squad, so while it's not an advantage that our teams were knocked out, it gives us valuable (additional) time to prepare the team for the Tri-Nations," said De Villiers."We will also use the Currie Cup and the respective unions' conditioning experts to prepare the players. Players must know that the Currie Cup will always be a measure for them to prove themselves. We want to let certain players get game time in consultation with the provinces so that we can get them sharp."De Villiers indicated that he is eager to pick Heinrich Brüssow for the Tri-Nations. The Free State flank last played Test rugby in November 2009."If he's declared fit I'd love to see him in action in the Tri-Nations."