All Blacks second-five Quinn Tupaea is in doubt for next year's Rugby World Cup, with further scans revealing more damage to his anterior cruciate ligament (ACL) in his left knee.
Tupaea, 23, also ruptured his medial collateral ligament (MCL), after Wallabies lock Darcy Swain attacked his planted leg in their Bledisloe Cup victory at Melbourne this month.
The Chiefs midfielder was expected to only miss three months, but will now need surgery on his ACL, ruling him out of action for nine months and next season's Super Rugby campaign.
With the World Cup less than a year away, he will race against time to prove his fitness and earn a spot in coach Ian Foster's squad for France.
Foster was left fuming after Swain's cleanout, which saw the Wallabies bad boy banned for six weeks for the incident.
"We've got a big issue with it," he said post-match. "We've got a player who's putting [Tupaea] out for nine months and you're not allowed to target legs on the side at a cleanout past the ball, so the rules are pretty clear.
"It looked dangerously like an ACL, which is a very, very significant long term injury."
Whereas Wallabies coach Dave Rennie played down the severity of the challenge and instead pointed at the opposition's potential foulplay.
"It was clumsy and reckless," Rennie said. "There's no malice in that… it certainly met the red-card threshold and he got punished accordingly.
"I hear they're fuming. We're not that excited about Fletcher Newell's clearout on Scott Sio, which leaves him out for three weeks, and he didn't get cited or carded during the game… they mentioned that he should have been cited as well.
"In the end, you can't use it as a defence, but we just highlighted the fact that we've got one incident that's been picked up, punished on field and off field, and another example that's been glossed over.
"We're not happy with the action and we're not happy with the result, but it's not malicious. He's been punished and six weeks is a hefty punishment, I reckon, and obviously fitting."
