England scrum-half Danny Care's chances of playing in the first Test have only been rated as '50-50' by Stuart Lancaster.
The influential number nine is coming off an excellent season with Harlequins and was one of England's top performers in the Six Nations.
Care however is carrying a shoulder knock, putting his place to start at Eden Park in doubt. Ben Youngs will start if Care doesn't come through Friday's fitness test.
"Danny is 50-50 I'd say at the moment. We want to make sure we're doing right by him," said Lancaster.
"To go into a Test against the All Blacks with anyone who is not 100 per cent physically and mentally would be a poor decision, so we need to make sure he's 100 per cent right.
"I also have my mind on the fact there's more than one game in this series, so I want to make sure I'm doing right by him.
"I know he's desperate to play because he's been exceptional in the Premiership and for us this season. We have to do the right thing.
"It would be a big blow losing him, but that would be lessened by Ben whose form picked up at the end of the season.
"If you go back to the game in 2012 when he started against New Zealand, that was him at his best and he's approaching that form now."
Should Youngs start, England will be forced to break their policy of not selecting players who participated in last week's Premiership Final, with Lee Dickson called into action on the bench.
"Lee's excited. He's just played in a final, he's won it and is absolutely buzzing," added Lancaster.
"He didn't train today and we need to manage him carefully. As soon as we knew about Danny we got word back to him in England.
"He started adjusting his time and sleep patterns from England to make sure he's adjusted. He'll be ready, no problem."