Injuries to Sam Whitelock and Liam Messam pose a selection conundrum for All Blacks' coach Steve Hansen as they prepare for their Rugby Championship clash with South Africa next week in Wellington.

Whitelock damaged his rib cartilage midway through the first half of the All Blacks' 28-9 victory over Argentina at McLean Park on Saturday, while Messam injured a quadriceps muscle when he scored a try.

"He's sore. He's got a rib cartilage rather than a rib fracture," Hansen told reporters on Sunday about the extent of Whitelock's injury. "We will see over the next few days how that comes right. Worst case he's out for four weeks, best is three.

"Yeah, he's (Messam) not OK. He has done a quad and again he's three to four weeks off as well."