All Black fly-half Aaron Cruden is set to miss this year's Rugby World Cup after rupturing a knee ligament, his Super 15 team the Waikato Chiefs said on Monday.

The 26-year-old limped off in the first half of the Chiefs' 26-9 win over the Canterbury Crusaders on Friday night and a scan on Monday confirmed the extent of the damage.

"Aaron will see a surgeon on Wednesday to arrange a knee reconstruction -- expected return to play time for this surgery is six months," the Chiefs said.

The timeframe make it virtually impossible for Cruden to join the All Blacks for the World Cup in England in September-October.

"It's obviously hugely disappointing for Crudes and we will be supporting him as he goes through this tough time and we wish him all the best with his surgery and rehab over the next few months," All Blacks coach Steve Hansen said.

Hansen added: "As selectors we plan for these unfortunate events and are constantly looking to build depth in all positions across the team."

The All Blacks have plenty of cover at pivot, with Dan Carter, Beauden Barrett and Colin Slade all wearing the number 10 jersey at Test level.
Source: AFP