DUBLIN (AFP) - New Zealand coach Steve Hansen has overhauled his starting line-up to ensure fresh legs as the world champions All Blacks look to complete a perfect season against Ireland on Sunday.

He made seven changes to the run-on team that defeated England 30-22 last weekend, concerned that fatigue at the end of a gruelling season could derail the quest to complete 14 wins from 14 Tests.

"It's a reflection of the physical nature of the whole year really, particularly the last nine weeks. We've gone around the world twice - this will be our seventh Test in nine weeks," he said.

Hansen was forced to make two changes for the Lansdowne Road clash, with star fly-half Dan Carter and prop Tony Woodcock out injured, but said he decided on a more extensive revamp to give some players a break.

"We've got the ability sitting there that is fresh so why not use them?"

No international team in the professional era have enjoyed a perfect calendar year, with the All Blacks side led by Wayne Shelford - that won all seven of their Tests in 1989 - the last to achieve the feat when rugby union was still an amateur sport.

However, New Zealand themselves came close to it again when they won 11 games and drew one in 1997.