Dan Carter's ageing body is causing concern for All Blacks coach Steve Hansen, who referred to him today as a "red-flag athlete".
The first-five has been scratched well in advance of this Saturday night's Rugby Championship test against South Africa in Dunedin as he continues to be hampered by a calf niggle.
The ailment forced him to miss the All Blacks' 21-5 victory over Argentina last night which thrust Aaron Cruden into the limelight for his fifth test start in his 13th appearance for New Zealand.
"He's getting older isn't he? And the more you play the game the more vulnerable you are to injury and he's got quite a few miles on the clock," Hansen said of Carter today.
"So that's just standard for any older player and he's got to be smart. We've got to be smart in how we deal with it.
"Just at the moment it's about getting him on the park now. It's as much about that as it is about the long term. He's what we call a 'red-flag athlete'. He's a high risk of getting re-injured so we have to be smart about the wear and tear of his body and how much pressure we put him under."
Carter's latest problem comes after the serious groin injury which ruled him out of last year's World Cup. He also suffered a hamstring strain that caused him to miss New Zealand's third test against Ireland in June.
He was taken off goalkicking duties for the Crusaders for a period during this year's Super Rugby competition as coach Todd Blackadder looked to limit the stress placed on his body as he returned from groin surgery.
Carter might be only 30, which is hardly ancient in rugby terms, but he has played huge minutes during the past decade in racking up 89 test appearances, 110 Super Rugby outings and just under 30 games for Canterbury at provincial level.
He debuted for Canterbury in 2002 and made his maiden appearances for the Crusaders and the All Blacks the following year.
Last year he signed a four-year deal with the New Zealand Rugby Union, which also has an option for him to take another sabbatical, but his last excursion offshore saw him suffer a serious Achilles tendon injury while playing for French club Perpignan in 2009.
Carter's absence, which isn't expected to be long term, will give Cruden another chance to run the cutter and he will probably start for the All Blacks against South Africa this weekend.
The Manawatu 23-year-old didn't set Westpac Stadium alight but the All Blacks eventually ground Argentina into the turf and Hansen had a clear idea of what he wanted to see from Cruden against the Springboks.
"More control. More consistency. Better decision making. But that's the whole team," Hansen said.
"We are playing to be better all the time and he's no different. But nines and 10s, they're the main computers of the team. They run the side and move them around the field the way you want them moved round and we didn't play smart football in the first half [against Argentina]."
Cruden's Manawatu teammate Aaron Smith also had a tough night against the Pumas and the young halfback may be replaced by Piri Weepu this weekend, which would provide a more composed look to the backline.