England represent the devil

England represent the devil Steve Hansen doesn't know, meaning all the cards aren't stacked in the All Blacks' favour at Twickenham.

The world champion tourists and third-ranked hosts renew their rivalry on Saturday, five months after New Zealand swept the home series 3-0.

Two tight Tests were followed by a 36-13 blowout in Hamilton against a tired English outfit.

Since then, the All Blacks have played eight Tests while England haven't played, the sort of comparison which weighs heavily in the favour of coach Hansen's men.

However, he is not only wary of the fatigue factor near the end of another long season, but also the unexpected.

Hansen says counterpart Stuart Lancaster has had two weeks behind closed doors with England, who may well have tweaked their tactics from the unexpectedly ambitious efforts of June.

"Do they stick with the adventurous game they want to play or do they think: 'No, we'll take them on up front'?

"So there's an advantage there - and they've seen what we've done since Hamilton."

The All Blacks are ignoring England's heavy injury toll, noting that nine players who started in Hamilton will face the haka on Saturday.

New Zealand are vastly more experienced than the hosts, boasting 759 caps to 359, but Hansen says that will count for little if the attitude isn't right.

There are two Tests this year in which he says they let themselves down mentally - the draw with Australia in Sydney in August and the first 20 minutes of the loss to South Africa in Johannesburg last month.

They won the nine other Tests, but were fortunate to squeak victory over Australia in Brisbane last month before the virtual exhibition win over the United States to start the tour.

Hansen says the Chicago week has proved to be good value for revitalising the players before the slog of three Tests in the UK.

Now they have to back their game plan to maintain a record of winning 34 of their last 35 northern hemisphere season-end tour Tests.

"There's no doubt our skill-sets have got way better and when we execute them well, we're a hard side to beat."

Daniel Gilhooly, NZ Newswire

London (AFP) - As if an injury-hit England did not have enough to contend with when facing world champions New Zealand on Saturday, they will be up against a "massively better" Sonny Bill Williams according to All Blacks coach Steve Hansen.

Last week's 74-6 thrashing of the United States in Chicago saw serial code-hopper Williams return to international rugby union action for the first time since August 2012.

Now Hansen is keen to see how the dynamic centre, who scored two tries against the Eagles, fares against 2015 World Cup hosts England.

"We saw what he was like against a tier-two nation, we want to see what he's like against a tier-one," Hansen told reporters at the squad's London hotel on Thursday.

"We haven't got a lot of Test matches between now and the World Cup starting so we need to get some answers."

Not that Hansen was in much doubt regarding the talent of the 20-times capped Williams, who has also played rugby league and boxed professionally

"He's always been an instinct type of athlete, that's why he's such a good league player, why he's a good boxer -- he's got good instincts, good ability to adapt and adjust," Hansen said.

Williams began his career in rugby league, winning the 2004 NRL title with the Canterbury Bulldogs in his debut season before walking out on the team mid-contract to play rugby union in France.

He contributed to the New Zealand 2011 World Cup win and snared the 2012 Super 15 title with the Waikato Chiefs before returning to the NRL with the Sydney Roosters last year, picking up another title with the side.

- Growing understanding -

And Hansen said the time he'd recently spent away from rugby union would make the 29-year-old Williams a better player in the 15-man game, citing the example of another code-switching World Cup-winner in former New Zealand lock Brad Thorn.

"It's a lot easier coming back for the second time, I think," Hansen explained. "The same thing happened to Brad Thorn.

"They struggle when they first come into the game because they don't understand it but then they go back to another sport but at the same time they keep watching the game they've come from and keep growing their understanding.

"I think that's what Sonny has done very well. He's always known he's going to come back to rugby (union) at some point and he's just kept watching the game and growing his learning and understanding of how to play the game."

Hansen, asked if Williams, known for both his power and ball-handling skill was a better union player now, replied: "Massively better".

Meanwhile fly-half Aaron Cruden, who will be alongside Williams on Saturday, said the midfielder's evolution as a player was also a matter of rugby intelligence as well as physical skill.

"Sonny is a phenomenal athlete, physically and mentally," Cruden said.

"He works really hard at his game, he?s a true professional. I know even in the short time he has been with us for a few weeks, he?s always asking questions, he?s picking people?s brains, he?s talking to the coaches, he?s having a lot of rugby specific conversations.

"It?s pretty incredible even his performance last week. He had been out of the game for almost two years and to come back and perform the way he did, I think he will gain a lot of confidence from that," Cruden added.

"For guys like us (Cruden and half-back partner Aaron Smith) who are not the biggest in the team, it?s nice to look outside you and know there?s a pretty dynamic player like Sonny there to give you a little bit of go-forward."