Liam Messam and Sam Whitelock have been ruled out of the All Blacks' Test against the Springboks in Wellington.
Both players left the park early in the 28-9 victory over the Pumas on Saturday and have subsequently been ruled out for up to four weeks.
The news will come as a blow for coach Steve Hansen as he prepares his side to face South Africa who, like the Pumas, tend to take a more forward-oriented approach.
Jeremy Thrush and Sam Cane are the obvious replacements, having slotted in with success against the Argentinians.
Should Hansen opt for more grunt up front, Blues flanker Steven Luatua might be considered for the blindside role, while fellow Blues player Patrick Tuipulotu should make his return at lock against the Boks more likely from the bench.
With the Test against Argentina a thing of the past, Hansen has turned his attention to Heyneke Meyer's Springboks.
'There's been a lot of talk already from them about how they want and need to beat us because they haven't done so [in the Rugby Championship],' said Hansen. 'We know what we're going to get and that's a fired-up side so we need to prepare for that accordingly and be in the right frame of mind.'
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