''If he has a good series and leads from the top of the order, then South Africa are bound to do well,'' Kirsten told Reuters.
''When he and (opening partner) AB de Villiers play well together the sky is the limit.'' Kirsten said he believed Smith's double burden could be an asset if the runs flowed from his bat.
''We need to remember that he is the captain and that he bats at the top of the order,'' Kirsten said. ''Those are important factors, and if he is in form he will make a massive difference for South Africa.''
Kirsten said Smith would need to bat with more patience to make the most of his potential worth to South Africa's World Cup cause.
''I think Graeme must gear himself to scoring centuries,'' he said. ''I know he is aggressive and I realise that is a part of the gameplan, but sometimes he is overly aggressive.''
The physically imposing Smith's forceful play has become a hallmark of the team he leads. South Africa have sought to brand this approach by unveiling their ''brave cricket'' campaign.
The move has been derided, but it is difficult to deny that Smith's elevation to the captaincy has coincided with the rise in confidence South Africa have shown on the field, particularly at the batting crease.
A case in point remains the series-deciding fifth one-day international against Australia in Johannesburg on March 12, 2006.
Australia scored what was for a few hours a world record total of 434 for four. South Africa overhauled it with a ball to spare, totalling 438 for nine to win by one wicket.
Smith's 90 off 55 balls was overshadowed by Herschelle Gibbs' 175 and Mark Boucher's unbeaten 50, but it is doubtful whether anyone else in the team could have kept his head as well as Smith did while Gibbs smashed the ball to all parts in their stand of 187.
That, clearly, is what Kirsten was getting at.