New Zealand lock Sam Whitelock is a doubtful starter for the second Bledisloe Cup game against Australia in Auckland on Saturday after developing concussion symptoms.
Whitelock played all 80 minutes during the opening game of the series in Wellington which ended in a 16-16 draw but has developed headaches since then and will be assessed according to assistant coach John Plumtree.
"Sam had some headaches after the game," Plumtree said.
"So we'll work through the concussion protocols and we'll see how he gets on this week.
"Hopefully he'll be all right for the weekend."
Meanwhile, Beauden Barrett, who missed the game at Sky Stadium was seen training for a brief period on Wednesday.
With Richie Mo'unga and Jordie Barrett experiencing soreness in shoulder, the All Blacks have recalled Josh Ioane as cover.
"It looked like he (Barrett) was running pretty well," Plumtree said.
"He's looking likely, absolutely, but he was looking likely this time last week as well.
"Richie had a little bit of a stinger in the shoulder but nothing too much."
New Zealand have never lost Bledisloe Cup since 2003 and following the game in Wellington, the All Blacks and the Wallabies will face each other twice in the Rugby Championship on 31st October and 7th November in Sydney and Brisbane respectively.