World Cup-winning coach Graham Henry has committed the ultimate sin in rugby-mad New Zealand, suggesting it would not hurt the All Blacks if they lose a game before they defend the Webb Ellis trophy next year in England.

The All Blacks have lost just once since Steve Hansen succeeded Henry after the successful World Cup campaign in 2011, winning 32 of their 35 Tests. They have also drawn twice with Australia.

"Perhaps they need to lose a game at some stage ... I think that galvanises the team and makes them re-analyse their position": Henry on the All Blacks. Credit:Reuters

Including their World Cup run, the All Blacks have won 39 of their past 42 Tests and with one year to the day until next year's cup begins, Henry was sounding more of a warning for the side and public not to get complacent with their success.

"Perhaps they need to lose a game at some stage," Henry told Television New Zealand on Thursday. "I know I shouldn't be saying that, but I think that galvanises the team and makes them re-analyse their position."