A sense of timing decorated Tana Umaga's All Black career.

He knew when to take the tackle, run a decoy, offload or, as he did at the end of the Grand Slam triumph in 2005, wave farewell to the black jersey after 74 internationals.

Now his instincts have pulled him home from three years learning the coaching craft with Toulon to be player-assistant coach with Counties Manukau in the national championship.

It is a great coup for Counties and a boost for their profile to have the former All Black captain wearing the red, white and black colours from the late-June start to this year's series.

"I am excited, it has come round quickly but it is definitely time to come home," Umaga told the Herald last night.

A combination of factors provoked the decision. His family were growing up, he said, and wanted to be in New Zealand near relations. He also wanted to further his coaching career.

Counties ticked those boxes and he hoped to contribute and learn a great deal from coach Milton Haig.

"Tana is a perfect match for Counties Manukau," chief executive Phil McConnell said. "His mana, experience, professionalism and dedication are precisely what we need to take our team to the next level."

Umaga has not played for Toulon this season, but said he had trained regularly, was in good shape and thought it would take him only a few weeks to be ready to play.

He had learned a great deal about coaching from Philippe St Andre, at Toulon, and Frank Walker, with Wellington, Wayne Smith, with the All Blacks, and Murray Roulston, with the Hurricanes, had been huge influences.

Toulon had not lost at home this season and were tracking well towards the French playoffs which ran until the end of May.

"He will be leaving Toulon in much better shape than when he arrived," said Duncan Sandlant, managing director of Point Sports Management, who represent Umaga.

"That is in no small part due to his unique ability to be able to bring players from different nationalities, cultures, languages and egos together to build a successful rugby team."

Umaga said he had learned a great deal about himself, he had absorbed all the forces that were at play both on and off the field and what was required to deal with those situations.

"It is both frustrating and rewarding, but players always learn a lot from coaches and that is my role, to pass on my experiences and help the players through all sorts of situations."

He had watched the rapid development of Sonny Bill Williams in his transition from league and was sure he would make an extremely good rugby player.

Williams was finally injury-free and fulfilling his potential. He was playing centre but also trained in the forwards and Umaga said he had all the attributes to make an international looseforward.

Umaga said he did not know Williams' plans, nor was he aware whether former All Black tighthead Carl Hayman was in the mix for Toulon next season.

"I don't have a big say in recruitment," said Umaga.

"The lifestyle and culture is great, the money is good, the skies blue, but I don't know whether Carl is ready to return to New Zealand or not."