"From a game point of view I don't know what we will get. I'm not too bothered if we only get a little bit. I'll be excited if we get a lot, but it doesn't really matter for us. What matters is that he's back and understanding how we are playing now because we are playing differently to how we were when he left."
It says an enormous amount about the faith the All Black coaching staff have in Williams that they have been prepared to throw him into test football on the back of a couple of hitouts for Counties.
But with Williams, the known facts never quite tell the full story. He's given the selectors plenty of reasons to feel confident: to be sure they are not taking a risk with him.
For a start, he's in his usual immaculate physical condition. Williams is heavier than he's been, and yet leaner, too. At 108kg his skin fold measurement shows only 35mm of fat - easily the lowest in the squad and proof that his conditioning is all there and more.
His appetite for learning has not diminished and his conversion from league back to rugby began, in some aspects at least, before the Roosters were knocked out of the NRL.
"He's been really systematic in his approach and he has been for quite some time," says Hansen. "He's been training to play rugby while he was in Sydney - long before he finished with the Roosters. He had game plans sent to him the day he finished with the Roosters.
"He's been really professional and meticulous about his preparation which is one of the key things that make him such a good athlete apart from being a freak - naturally, genetically. His preparation skills are sensational."
Hansen isn't concerned, longer term, about Williams being able to switch back to rugby. Having had a year with the Crusaders, a year with the Chiefs and 19 All Black tests, he has has solid grounding.
It's not the same situation at all as when he first arrived in 2010 after two injury-plagued seasons in France. Back then he barely knew the game and what experience he had was not necessarily relevant in relation to the type of rugby he'd be playing in New Zealand.
Perhaps ironically, it is Williams' attention to detail that Hansen is a little worried about.
"He's already a mile ahead of where he was in picking the game up when he first came because he's had the advantage of playing for the Chiefs, Crusaders and All Blacks whereas last time he'd only played for Toulon," says Hansen.
"It wasn't New Zealand rugby and French rugby is different to our game. So he's got a feel for it. The only worry I have [about tomorrow] is that he gets over-prepared and overthinks it. After Thursday it is about letting his instincts kick in. When you put great instincts with a 6"4 guy who has got speed and power, things happen.
"It's just allowing him to get into his work and understand from a structure point of view that it won't be perfect but that's okay. Whatever he does, he will do well and we will work off it."
2008
Walks out on his Bulldogs contract and joins Toulon in the South of France where he is coached by Tana Umaga.
2009-10
Plays 33 games for Toulon and scores six tries. Announces in April 2010 that he has signed a one-year contract with the New Zealand Rugby Union.
2010-11
Plays six games for Canterbury before being called up for the All Blacks Grand Slam tour where he makes his debut at centre against England. Plays 15 games for the Crusaders in 2011 and makes the All Blacks World Cup squad where he started against Tonga and Canada and Argentina (on the wing). Signed a one-year deal with the Chiefs shortly after the tournament.
2012
Comes of age as a rugby player helping the Chiefs win their first title. Started five tests for the All Blacks at second-five before announcing he was leaving for Japan then the NRL.
2012-14
Has a season with Panasonic and then joins the Roosters, helping them to win the title last year. Re-signed for one more year and made the semifinals this year. Played for Counties four weeks after he finished in the NRL and now on tour with the All Blacks.
