Given their respective results, speculation has been rife about whether the Chiefs would part ways with Gatland and embrace McMillan, who forged immediate connections and evoked the best from the team.
The Chiefs moved to quell that conjecture in January when they signed McMillan as Gatland's assistant for the 2022 and '23 seasons.
Gatland's absence, coupled with McMillan's success, has since forced a rethink. The Chiefs have now remodelled the roles to leave McMillan in the head coach position, while creating a broad director of rugby role for Gatland.
Chiefs chief executive Mike Collins outlined how the structure will work.
"Gatty's vast experience and knowledge from provincial, Super and international rugby means he is uniquely placed to help develop Clayton as a head coach and support our wider coaching framework," Collins said.
"Clayton demonstrated this year both with the Chiefs in Super Rugby Aotearoa and with the Māori All Blacks that he is ready to progress. This structure allows us to get the best from both coaches."
Collins said the new director of rugby role would focus on supporting coaching staff and shaping the rugby and high-performance programme.
While slightly different, Collins likened the new structure to the set up that pushed the Chiefs to their maiden titles in 2012 and '13, when head coach Dave Rennie linked with former All Blacks coach Wayne Smith in a supporting role.
"We are stoked that both coaches have bought into this new approach, are keen to work together and that the new structure will allow both of them, and the club, to grow and develop."
Gatland, who has returned from the dour Lions series defeat in July, is keen to embrace the new role more commonly adopted in the Northern Hemisphere.
"No one was prouder than I was with the gains made by the Chiefs during 2021. It was outstanding to see both individuals and the group grow and achieve success and that includes Clayton, who brought his vision and mana to the head coach role," Gatland said. "I am excited at the prospect of working with Clayton and the other coaches to build on those foundations as we strive for success in the new Super Rugby Pacific in 2022."
McMillan is grateful for the support and faith shown in him by the Chiefs.
"Having lived my life in the Chiefs region, I am a Chiefs club man through and through and like Gats I want to see the Chiefs back at the top of the Super Rugby table," McMillan said.
"As I have said previously, we complement each other well and one of the major attractions for me when I joined the club was to work alongside Gats and benefit from his immense knowledge and experience. We are committed to working together to position the Chiefs for sustained success and I can't wait to get started."
New Zealand Rugby general manager of professional rugby Chris Lendrum said: "The Chiefs new coaching structure will get the best out of two quality coaches and that's a great result for the club, its players and fans.
"Clayton has impressed through his work with the Chiefs last year and with the Māori All Blacks and Warren's international experience will be a valuable asset in helping him continue his development.
"We are fortunate to have such a high quality of coaches across our teams as we head into the new Super Rugby Pacific competition in 2022."
