The All Blacks have a new injury concern ahead of the British and Irish Lions tour after first-five Beauden Barrett was a late withdrawal from the Hurricanes' Super Rugby clash with the Bulls in Pretoria having complained of mystery headaches.
Hurricanes coach Chris Boyd said the decision to withdraw Barrett was made after doctors were unable to isolate the reasons for his condition.
Barrett had taken a blow to his head in the 61-7 victory over the Cheetahs in Wellington last weekend, but had passed a concussion test at the time.
"When we came over here (to South Africa) he's had some headaches and the doctor was unable to differentiate between the altitude, the humidity, the air conditioning ... because when you come over here on a short turnaround, the headaches and those types of symptoms are pretty normal," Boyd said.
"But the fact that he couldn't isolate those out from the back-end of the game against the Cheetahs meant that we were very cautious and withdrew him out of the game," he said after his side's 34-20 victory over the Bulls.
The Hurricanes have already lost captain Dane Coles, who has been missing since the middle of March, to similar symptoms, but Boyd says the circumstances around Barrett's case are different as Coles' problems arose after he exercised.
"He (Beauden) was really different because every time he exercised, every time he trained, he got absolutely no symptoms at all.
"But the next morning he woke up with a headache, which probably eighty percent of the squad did because we're trying to get used to the altitude and trying to get used to the temperature and trying to get used to all sorts of things.
"But when you speak to the medical team, it's like what is inducing that? Is it a continuation of some head knock symptoms or what's going on? So we weren't able to differentiate from that and we pulled him out at Captain's Run yesterday (Friday)."
Barrett is the incumbent first-five for the world champion All Blacks, who play the first of three eagerly anticipated tests against the touring Lions on June 24.