Sydney - For the best part of Victor Matfield's playing career, opponents have attempted to find some way of stopping him - and for the most part they've failed, according Wallabies forward Dean Mumm.While the Springboks have been left reeling from three straight losses in the Tri-Nations, Mumm predicts that Matfield - their vice-captain - is set to drag them back to their best. And the Wallabies second-rower will do his utmost to stop the Bulls captain, who sits on 98 Test caps heading into Saturday week's Test against the All Blacks at Johannesburg, when he gets his chance.But Mumm knows that Matfield, who will reach 100 Tests when he runs on against the Wallabies in the first of two games on the Highveld the following week, will be primed and ready.While he agrees the absence of scrumhalf Fourie du Preez due to a shoulder operation will have an major effect on the Springboks, Mumm believes that Matfield is the team's true inspiration.''Fourie du Preez is out. That's the way the way it is,'' Mumm said. ''Victor is very much the heart and soul and a significant part of the mental framework that is South African rugby. He is coming up to 100 Tests. His influence is massive and something we have to be aware of.''Asked if it was possible to stifle Matfield, Mumm said: ''I don't know. There are plenty of people who have tried … and failed. You can be aware of what influence he has but don't give him any special sort of treatment.''Mumm rejected comments that Matfield needed a rest. ''He has been playing pretty well,'' he said. ''The lineout for the Springboks wasn't great against the All Blacks for the first Test but then Victor certainly rectified that in the next two Tests (against NZ and Australia).''He is too good a player not to get that lineout up and running again to its full capacity. But in terms of his play around the field, he is a very intelligent player. The work ethic that he has had has been really good. If he can continue to play well, he is going to pull the rest of them in.''Australia have not won on the Highveld, where they will play the Springboks at Pretoria and Bloemfontein, since 1963.''It's an exciting challenge for us to go over there to an intimidating crowd,'' Mumm said.''It's a big environment. They will have regrouped. I'm sure they will be as strong as they have been in recent years.''I've had a (Super 14) win at Bloemfontein. I haven't been lucky to win at Pretoria but the crowd has as much, if not more, passion than when at Super 14. If you change your mindset and think it is a wonderful challenge … well, I think we should.''They Wallabies will reconvene in Sydney for their next training camp on Monday.