The Blues tighthead only lasted six minutes on the pitch after replacing Ben Franks in Saturday's 40-7 win over South Africa.
And All Blacks coach Graham Henry doesn't hold high hopes for his front-rower to be fit for this weekend's Test against the Wallabies at Eden Park.
"The reports are not as good as I thought they were going to be. He doesn't look as positive as we thought it was last night," he said.
A surgeon has yet to look at scans of the injury so there was still some doubt over the extent of the fracture for the 32-Test prop - who will join Ulster after the World Cup.
With Tony Woodcock set for some much-needed game time in the ITM Cup for North Harbour on Tuesday, Henry said it's likely they would bring another prop into the squad to assist with training with Wellington prop Neemia Tialata and North Harbour's Ben Afeaki possible back-up options.
"'It wouldn't be a player we would bring in to play in the Test, I wouldn't have thought - someone who can help us with training."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.