Cape Town - Nick Mallett says the Springboks' lock stocks look particularly promising with next year's Rugby World Cup in mind.As it happened: South Africa v ScotlandThe former Bok coach was speaking in the SuperSport studio after South Africa's 55-6 win over Scotland at the weekend.With Eben Etzebeth and Pieter-Steph du Toit out injured, Cheetahs youngster Lood de Jager stepped up alongside Victor Matfield.And with Flip van der Merwe and Bakkies Botha also in the mix for next year's World Cup in England, Mallett said coach Heyneke Meyer should not have sleepless night over this position."In Victor you have a player whose strong point is not hitting rucks, so you have to have a forward who does that. He's played all his life with Bakkies Botha. We're very fortunate in South Africa to have Eben Etzebeth, who can do the same job, and this youngster Lood de Jager, who came through last year. And even in Super Rugby in a slightly battling Cheetahs team he has always proved that he's very physical. He's had two great caps now for the Springboks, he's been so physical, knocking the guys back. Looking at the locks for the World Cup, I think Pieter-Steph du Toit did enough to be in the running. You've got now between Bakkies, Etzebeth and Lood de Jager as options as your No 4 lock. There's plenty of options and that's a nice position to be in," said Mallett.One area in which the Boks struggled was the scrums, something Mallett admitted was a worry."We are still not convincing in the scrums. It's the one area of the game that I worry about. Our lineouts are solid, our driving mauls are well organised, we have a good exit strategy, a good kicking game, great ball carrying forwards, backs who hit the advantage line at pace, a very creative fullback and good pace on the wings, but if Jannie (du Plessis) gets injured we're in a bit of trouble. "We didn't use this June as an opportunity to blood a new tighthead. We gave Coenie (Oosthuizen) a bit of a go and it arguably wasn't a great success. Here was perhaps an opportunity to give a longer time to Marcel van der Merwe, but he played a lot of the game at loosehead. "Bismarck du Plessis has also played a tremendous amount of rugby this season, so those brothers have held both the Sharks' front row together and the Springboks' front row together for a very long time and they need to be rested. In the same way that we've rejuvenated a lot of players by bringing youngsters into their positions and helped to produce competition, we haven't done that up front."