When Springbok coach Heyneke Meyer visualised his perfect starting team for a World Cup quarterfinal after he took the job in 2012, the No 5 position contained the name Victor Matfield. At the time, Meyer had never even heard of Lood de Jager.But visualisation does not take in the reality of the vagaries of a brutal contact sport, age and a nigh inexplicable rise of one player.So it's De Jager, 22, who will start against Wales on Saturday at Twickenham, with Matfield on the sidelines hoping there will be a chance in a semifinal next week.The only change to the starting 15 from the team that beat the US 64-0 in the final Pool B game is on the right wing, where experienced, in-form JP Pietersen returns at the expense of Lwazi Mvovo.On the bench tight-head Jannie du Plessis, hooker Adriaan Strauss and scrum-half Ruan Pienaar replace Coenie Oosthuizen, Schalk Brits and Rudy Paige.But, while South Africa may have lost the services of Victor Matfield, it is scrum-half Fourie du Preez whom coach Heyneke Meyer desperately needs to stay fit.Meyer admits he had "been on his knees" convincing Du Preez to fight for a place in the Bok side after a series of serious injuries threatened to end his career.Now it's Du Preez who has repaid his faith with commanding performances in the past three weeks, which have kept alive the Boks' hopes of a third world title.Meyer has dismissed speculation that this might be his last match in charge if the Boks fail to beat Wales."If you start thinking about that then you have given up," Meyer said. "If you are not confident and don't believe in the team, it filters back to the players."I'm just here to serve; I take it game by game. Hopefully there are a few more weeks left in us, but we have to play well and we have to beat Wales because we are the Springboks; it's as simple as that."Our teamBok starting lineup:15 Willie le Roux, 14 Bryan Habana, 13 Jesse Kriel, 12 Damian de Allende, 11 JP Pietersen, 10 Handré Pollard, 9 Fourie du Preez (c), 8 Duane Vermeulen, 7 Schalk Burger, 6 Francois Louw, 5 Lood de Jager, 4 Eben Etzebeth, 3 Frans Malherbe, 2 Bismarck du Plessis, 1 Tendai Mtawarira.Reserves:16 Adriaan Strauss, 17 Trevor Nyakane, 18 Jannie du Plessis, 19 Pieter-Steph du Toit, 20 Willem Alberts, 21 Ruan Pienaar, 22 Pat Lambie, 23 Jan Serfontein...