Richard Kahui is believed to be ready to sign a deal to play in Japan, leaving the All Blacks dangerously short of midfield players.
Compounding the problem for the coaching panel, the Herald understands that Conrad Smith will not be available to tour Europe at the end of the year - instead resting and recuperating in a bid to rejuvenate himself after 10 punishing professional seasons.
Tamati Ellison, who established himself as the preferred back-up second-five last year, is recovering from shoulder surgery and is not expected to be fit until the latter stages of Super rugby, while hopes are fading that Sonny Bill Williams will return to the code next year.
With Cory Jane also ruled out for an indefinite period with knee damage, an important area of strength for the national team - depth and quality of outside backs - has been compromised before the season has even begun.
All Blacks coach Steve Hansen has been aware of Smith's plans for some time, which is partly why Highlanders' utility back Ben Smith was groomed at centre during the Rugby Championship and end-of-year tour.
But the loss of Kahui, after his campaign with the Chiefs, would be unexpected and damaging.
The 27-year-old, who missed the international season last year after shoulder reconstruction - his fourth - is an outstanding test player at either centre or wing. The All Blacks view him as a critical part of their armoury but the damage inflicted on Kahui since he burst on to the provincial scene in 2006 has been severe and constant.
He was a contender to make the 2007 World Cup squad until injury ruled him out and since making his test debut in 2008 he has collected only 17 caps. He has had only two seasons - 2008 and 2011 - without incurring serious injury and he admits that after being ruled out for six months last April after a shoulder dislocation, the litany of misfortune left him questioning his longevity.
"It is not just a game for us, it is a livelihood, it is a job," Kahui said. "All this comes into play and I have had four shoulder ops so you start thinking pretty seriously about your career and life after rugby.
"While it is not an exciting thought it is a reality and if you do all you can to prepare yourself for that while you are playing footy, you feel a lot more comfortable about it."
Kahui comes off contract this year and while he says he won't make any decisions about his future during the Chiefs' campaign, it's understood that he is close to agreeing terms with one of the leading Japanese clubs.
The prospect of making serious money over there while he can is proving hard to resist and a two-year deal would enable him to return to New Zealand to play Super rugby in 2015 and possibly push for a World Cup place.
BACKS TO THE WALL
Conrad Smith
Has a sabbatical clause in his contract that he will use this year when he skips the end-of-season tour to England, Ireland and France.
Tamati Ellison
Rated a test-class second-five but returned from the end-of-season tour with historic damage to his shoulder that needed surgery. Not expected to return until after June.
Richard Kahui
On the verge of committing to a contract in Japan.
Cory Jane
Busted his knee in pre-season training with the Hurricanes. Requires surgery and unlikely to be seen for a minimum of six months.
Robbie Fruean
The bullocking Crusaders centre has historic health issues related to heart surgery he had in his early 20s.
