Rassie Erasmus has used Monday's selection briefing to explain why Wilco Louw was left out of the Springbok 23 to face England at Ellis Park next Saturday, while also confirming that uncapped lock Riley Norton has suffered a grade-three hamstring tear that rules him out for eight to ten weeks.

With Thomas du Toit named to start at tighthead and Stormers rookie Zach Porthen on the bench, Erasmus cited a combination of workload, personal hardship and the specific demands of the England match as the reasons Louw was passed over despite his experience and his recent Premiership final appearance with the Bulls.

"Wilco has had a tough time. Not to get into his personal life, but there was some illness in the family. There was a family bereavement; he was ill for one game and had a tough last five, six weeks," Erasmus said. "We think his body took some hammering in the last couple of weeks, so that's the reason."

Erasmus also pointed to England's youthful, mobile profile as a factor favouring Porthen. "Zach is definitely scrumming against guys like Ox and Gerhard Steenekamp and is doing a really great job. If you look at the team of England, it's a youthful team and a mobile team and we feel we might need that in the game."

Norton's injury is a significant blow. The 20-year-old impressed against the Barbarians and was earmarked to earn his first cap against England before being released to the Junior Boks for the Junior World Championship in Georgia. That plan is now abandoned. "Riley pulled his hamstring, a grade three, so that is bad for him — eight to ten weeks," Erasmus confirmed, adding that Norton is unlikely to be available before September.

Norton is the second young lock to pick up a hamstring injury in the Springbok training environment. Jaco Williams suffered a similar problem but has since returned to full fitness. Erasmus acknowledged the intensity of senior camp sessions as a likely factor for younger players. "The junior guys coming in, maybe the intensity at the beginning of the training sessions — for the younger guys, it's about getting used to keeping up with that intensity all the time."

The injury has left Erasmus without a specialist lock on the bench, opting instead for a five/three split with Pieter-Steph du Toit designated to cover the second row if required.

Saturday's match will also see Cheslin Kolbe and Damian Willemse reach 50 caps apiece, with Manie Libbok starting at out-half.