Crusaders assistant coach Daryl Gibson has quit suddenly, saying he doesn't want to be solely a defence coach next year.

Crusaders Chief Executive Officer Hamish Riach said Wednesday that Gibson had informed them that he has decided not to continue in the franchise's coaching team next season and has tendered his resignation, effective immediately.

"It is time for me to forge my own path now, as shown by many Crusaders assistant coaches such as Colin Cooper and Vern Cotter who have gone onto other exciting things," Gibson said.

Gibson's coaching responsibilities changed after the 2012 Super Rugby season and his new role in 2013 was going to focus specifically on defence.

Head coach Todd Blackadder said the restructure changed Gibson's thinking.

"Obviously he's had some time to reflect and come to the conclusion that it really wasn't quite for him and I really respect that," Blackadder said.

Gibson's resignation means the Crusaders will review their coaching setup and appoint a new assistant with backs experience before assessing other options.

He said he had had a fantastic four years with the Crusaders, but was he was "very excited about the future and I see this as a positive change in my rugby career".

His next role will be assistant coach to Jamie Joseph for the Maori All Blacks' three-match tour of the United Kingdom in November.

Crusaders chief executive Hamish Riach and head coach Todd Blackadder said it was sad to see Gibson go but they wished him well.

With Gibson's resignation the Crusaders would reconsider their two coaching roles.

Gibson, a midfield back, was a founding member of the Crusaders franchise in 1996 and played 77 games for them.

He played 19 Tests for the All Blacks between 1999 and 2002.

Sources: NZ Newswire & Newstalk ZB