New Zealand Rugby high performance manager Don Tricker has resigned to take up a position with US baseball outfit the San Diego Padres.
NZR chief executive Steve Tew said Tricker's contribution to the organisation, in particular to the All Blacks coaching and management team, had been significant.
He started officially at NZR in 2010, but had been involved prior to that as a "highly regarded" performance consultant.
Tew said Tricker was a key influence for the All Blacks following their disappointing 2007 Rugby World Cup campaign, where they were knocked out in the quarter-finals by France.
"Don has been a critical part of our teams' and organisation's success over the past decade," Tew said.
"In many ways, he's been our secret weapon, with sports from all around the world seeking to understand the structures and elements that make the All Blacks so successful."
All Blacks coach Steve Hansen said Tricker had been a great asset to NZR, and would be missed.
"Personally, I'd like to thank him for his support and unwavering work to help NZR improve at all levels including the All Blacks throughout my time as head coach.
"He leaves big boots to fill."
Tricker, who takes up his new position early next year, said his work at NZ had played a key role in his development.
"The opportunities I've had in rugby have accelerated my growth both as a person and in the high performance space.
It had been a tough decision to leave his home town of Porirua, Tricker added.
"Much of what I know, and how I relate to people, comes from my upbringing in a strongly multi-cultural community.
"I'm forever indebted to the Porirua community for what it has given me."