New Zealand captain Scott Barrett is set to miss the inaugural Nations Championship Tests, including the 18 July clash with Ireland, while sidelined for up to five months to recover from back surgery.
His Super Rugby team, Canterbury Crusaders, confirmed the 32-year-old lock would go under the knife by the end of the week after non-invasive treatments had failed.
The All Blacks kick off their season against France on 4 July before hosting Italy and then Andy Farrell's side in Eden Park, Auckland in the Nations Championship.
They head to South Africa in August for a four-Test tour against the world champions.
Barrett started the season on a non-playing sabbatical and had surgery on a troublesome ankle and Achilles problem.
His plan to return to action for defending champions Crusaders in late April was put on ice due to the back struggles.
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Crusaders coach Rob Penney said Barrett was frustrated by it all.
"But he's got his head around it now, a pretty special trip to South Africa that he’s going to miss, and some other bits and pieces," former Munster coach Penney said on Wednesday.
"But, ultimately, he’s just got to get himself right."
Loose forward and occasional skipper Ardie Savea is the standout candidate to take the All Blacks captaincy under new coach Dave Rennie.
Barrett's Crusaders and All Blacks team-mate Will Jordan may also miss the start of the Test season having been ruled out of the rest of the Super Rugby campaign with a calf problem.
The Crusaders host leaders Wellington Hurricanes in Christchurch on Friday seeking a victory to give them a chance of hosting their first match in the play-offs.
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