The man touted as the next coach of NSW and a future Wallabies coach has opted for a job under Steve Hansen instead.

Waratahs forwards coach Simon Cron will join Japanese Top League club Toyota Verblitz as head coach under Hansen at the end of this season.

Moving on: Simon Cron, left, and head coach Daryl Gibson consult at training in February. James Brickwood

Though neither Cron nor Hansen have confirmed their moves, it is understood NSW Rugby chief executive Andrew Hore let board members know Cron was moving on over the weekend.

It is a major blow to the Waratahs, who had considered the Shute Shield-winning former Norths coach the frontrunner to replace Daryl Gibson at the end of next season. He is also highly rated by Rugby Australia.

It will also send shockwaves through the NSW playing group at a sensitive time, when they are in South Africa with their finals hopes on the line over the next two rounds.

The news will hit some of the Waratahs' forwards particularly hard, many of whom he coached at Norths.

Rob Simmons has enjoyed a mid-career revival at the Waratahs over the past two seasons. AAP

He has brought the best out of a number of talented but underperforming players, including Rob Simmons, Ned Hanigan, Michael Wells and Jed Holloway, and bringing through others, such as Harry Johnson-Holmes.

Cron is understood to have been disappointed that NSW opted to renew Gibson for an extra year in February. The Waratahs wanted to keep their ambitious assistant but had stopped short of guaranteeing him the head coach's role in 2021.

The move all but closes the door on Cron taking the head coach's role at the Waratahs under Hore's administration and the current NSW board.

Hore told News Corp last week that the organisation wanted Cron and Gibson to stay together next year, and beyond that there were no promises.

"We would like him to stay with Daryl next year, he’s got areas we would like to see improvements and hopefully put himself in a strong position to lead the Waratahs and then Australia," he said.

"There’s no promises in and around being head coach, there are other names there as well.

"Simon has got to show us he is prepared to grow in some areas. Daryl has continued to grow — he got off to a rough start and he’s had to look at how he tailors his environment and we’ve started to see the improvements."

New Zealand-born Cron is from a Canterbury dynasty that has produced a number of talented coaches, including All Blacks forwards coach Mike Cron, his uncle, and Hurricanes assistant coach Dan Cron, his cousin.

But he and wife Aimee have spent the last 13 years raising their family in Australia, with Cron coming up through the club rugby ranks to coach Norths to their first premiership in 41 years in 2016.

Simon Cron led Norths to their first Shute Shield premiership in 41 years in 2016. Dominic Lorrimer

He was then given the Australian under-20s - now the Junior Wallabies - before being snapped up by the Waratahs to coach their forwards ahead of the 2018 season.

Hore said last week the Waratahs had put their best foot forward in an effort to retain him.

"We’ve had dialogue with him and an exchange of views, we would like to think we’ve put our best foot forward to what’s best for him, his family, and his development as a coach," he said.

"The best position for the team and the organisation is to hopefully have continuity. He needs to think this through carefully, it’s his future, and he needs to figure out what development he wants to get out of his coaching career."

The news could not come at a worse time for the organisation, which is dealing with poor attendances, the ongoing Israel Folau drama and a team that is a real chance of missing out on a play-off spot the season after reaching the semi-finals.