Luke Jacobson, the surprise selection as an All Blacks loose forward for the Rugby World Cup, has been ruled out of the Rugby World Cup with ongoing concussion issues.
The decision was taken on Friday and Jacobson will be replaced by Tasman's Shannon Frizell.
All Blacks head coach Steve Hansen said Jacobson, 22, had not shown any signs of concussion after the Tonga test last Saturday, but developed symptoms after the first training session in Japan this week.
"While it was a tough conversation to have, ultimately it was a very simple decision. We have a duty of care to look after our players and Luke's health is the most important thing above anything else."
"We all felt that the best thing for him to do is to take a break from rugby until he is symptom-free and ready to return to rugby.
Hansen said he was sure Jacobson would get the chance to play at another Rugby World Cup.
Jacobson said he was "gutted to be missing the Rugby World Cup", yet he understood why that should be.
"I've been feeling pretty good when I've just been doing my normal thing around the hotel but it's probably more when I go to training. It’s when I start to try and run around, pass the ball around, that sort of thing, that I really start to feel it," Jacobson told reporters.
He said that by taking a break now, he'll give myself the opportunity to continue his career in the future.
Jacobson will stay with the All Blacks until he is symptom-free and ready to fly home.