By Greg Stutchbury
OITA, Japan (Reuters) - The speed at which Japan attacked Ireland would be hard to live with for any team and the All Blacks will need to learn how to combat their style of play if they meet in the quarter-finals, New Zealand coach Steve Hansen said on Monday.
Japan caused an upset of the same proportion as their win over the Springboks four years ago when they defeated Ireland 19-12 in Shizuoka on Saturday.
The match could have repercussions for the All Blacks, who could potentially face the hosts in the quarter-finals and while Hansen said he was only focussing on their Pool B game against Canada on Wednesday, he was still impressed by Japan's win.
"They did give us plenty to think about," Hansen told reporters at the team hotel in Beppu. "Their speed of ball was great, their line speed was awesome, they just kept coming, time after time after time.
"We like to play fast, I don't know if we want to play that fast or if we can play that fast in the humidity we're playing in.
"It certainly affected the Irish, that speed of the game."
Hansen added the hosts' win was good for the tournament and while they could still win Pool A and avoid the All Blacks in the knockout phase there was also a chance they could finish runners-up and meet his side in Tokyo.
"It's important at the Rugby World Cup that you don't think too far ahead as plans change all the time," Hansen said.
"If we have to play Japan then we will prepare accordingly and we'll expect what we saw the other day, them coming at us 100 miles an hour and wanting to turn opportunities into fast ball.
"We'll have make plans to make sure they can't do that."
Hansen, who is stepping down after the tournament after 16 years with the team as an assistant and head coach, added that Japan coach Jamie Joseph could potentially take control of the All Blacks one day.
"Jamie Joseph's a very good coach, but he didn't become one overnight just because he coached Japan to beat Ireland," Hansen said of his fellow New Zealander.
"I always find it amusing, you beat someone and all of a sudden you're a super coach. I hold the world record for the most losses in a row and the world record for the most wins in a row, so what sort of coach am I?
"Coaching's a lot more than just the results. Is he good enough to be an All Black coach? I think he is one day.
"Am I picking the next coach? No. So there's not much point even asking what my opinion is because those people who are appointing him won't take any notice of it anyway."
(Editing by Christian Schmollinger)