Williams yesterday confirmed he was unavailable to play in the upcoming World Cup being played in the UK and France. It ended months of speculation but there is still widespread curiosity around what his next move will be with Kiwis coach Stephen Kearney saying yesterday all he knew was the 28-year-old was unavailable because of "other commitments".
Williams has also given little away, saying in the aftermath of Sunday night's grand final win with the Roosters he would reveal his move in a "couple of weeks".
"Wishing the kiwis all the best in their title defence, having my first break since 2008. Looking forward to spending time with fam n friends," he tweeted yesterday.
Kearney had taken an expect-the-worst-hope-for-the-best attitude around Williams all season so wasn't surprised by the decision. Jeremy Smith is also missing for personal reasons and centre Shaun Kenny-Dowall is out because of the fractured jaw he suffered in Sunday night's grand final win.
"We had planned for Sonny not coming away," Kearney said. "It was the general feeling I had throughout the year. We were planning that he wasn't going to come and most people were probably thinking that, too.
"It would have been great to have all three of those players [who are unavailable] with the group. They all add something and would have been great assets for the team but I'm really, really pleased with the team. The players who haven't been selected, I think that says a lot about the depth of our squad at the moment. I'm really excited about what we have to work with."
Williams' decision closes a sad chapter in his international rugby league career. He played only seven tests for the Kiwis, the last being in 2008, and was never on a winning side. The closest he got was a 16-16 draw with Australia in 2004.
He would have added genuine quality and x-factor to the Kiwis' 24-man squad but wasn't seen as a critical inclusion.
Souths hooker Issac Luke is irreplaceable and New Zealand would also not have wanted to do without five-eighth Kieran Foran, who had another excellent season with Manly.
This country isn't short of good second-rowers and back-rowers - even without Williams and Smith - but have less depth in the spine of the team.
Luke is the best dummy-half runner in the game and Warriors utilities Thomas Leuluai and Elijah Taylor will provide backup. Foran is also among the top tier of halves and his control and influence is critical. Again, Leuluai will provide backup.
Smith's absence is a blow, with the tough-tackling back-rower a key member of the 2008 World Cup-winning squad and the 2008 and 2012 New Zealand Player of the Year. It was a difficult decision to leave him out but it's understood the NZRL effectively made the decision for him after his partner recently gave birth to a premature baby.
"Jeremy would have been a real asset for the group," Kearney said. "It's hard to replace someone like Jeremy but, with the guys we have in the group, he won't be missed as much from a performance point of view as he would have done two years ago."
At the start of the year it seemed inconceivable the Kiwis would still be considered contenders for the title without Williams and Benji Marshall but there isn't a great sense of panic about their absence. And that's progress.