Sonny Bill Williams settled in for the calm before the storm, bursting with pride as his family shed tears of joy and relief.

At the end of two years ravaged by injury, New Zealand's talisman centre was fit, healthy – and itching to chase a historic third consecutive World Cup crown.

That Williams actually tuned in to watch Steve Hansen name the All Blacks' World Cup squad, with his family gathered round, underscored just how gruelling his injury woes had become.

Knee surgery threatened the 34-year-old's World Cup participation, and that after wrist, knee and shoulder injuries in the previous season.

Before the All Blacks weigh anchor for Japan and their bid to retain the Webb Ellis Cup they lifted in 2011 and 2015, Williams knew he had to pay reverence to the mental resolve that kept him from giving up the rugby ghost.

The former boxing champion and rugby league star converted to Islam in 2009, and rugby's most famous Muslim continues to credit his faith with increasing maturity and calmness.

"When you're praying five times a day and you're trying to pray not just with your limbs but with your heart, it just naturally happens," Williams told New Zealand's Radio Sport.

"You get knocked down but you've just got to get back up. To be honest, it has been really tough and I've had to show a lot of resilience.

"But I'm just proud. A skilled sailor was never made in smooth waters and I've definitely struggled in that respect over the past few years.

"I actually watched the naming for the first time, I watched it with my family.

"There were a few tears from my wife and brother and it really just made it feel real – this thing that you strive for, has paid off.

"I'm really excited to be here and now there's a job to do and that's to create history."

Asked if he ever considered quitting in the wake of a string of debilitating injury setbacks, Williams added: "To be honest, no. I try to live my life with the glass half-full mentality and that's what my faith gives me.

"I'm grateful to be able to live my life as a professional sportsman doing what I love. An injury here or there, it ain't no thing in the big scheme of things."

Blues star Williams is New Zealand's oldest World Cup squad member at 34, with Kieran Read continuing as captain in boss Steve Hansen's ranks.

Rookie prop Atu Moli has been included ahead of stalwart Owen Franks in the main selection surprise.

New Zealand have proved vulnerable across the last four years, drawing the Test series with the British and Irish Lions and twice losing to Ireland.

Even this year Hansen's men drew with South Africa then suffered a record loss to Australia in Perth.

The All Blacks battered Australia in the rematch after that hefty loss however, and remain the team to beat in Japan.

"You'd rather be favourites than not favourites," said head coach Hansen, shaking off any pressure of chasing a third straight title.

"You're going to see lots of form dips and things that don't seem normal, because it's not a normal year."