Milan - Former All Black lock Norm Maxwell believes the two-time defending world champions will have their work cut out to hold on to their title in Japan later this month.
"It's anyone's game," warned 43-year-old Maxwell at the end of a five-day 'All Blacks Clinic' coaching summer camp for children in Milan.
New Zealand - in the same pool as two-times winners South Africa, Italy, Namibia and Canada - open against the Springboks on September 21 in Yokohama.
"I have some hopes," said former Crusaders lock Maxwell, who earned 36 caps for the All Blacks from 1999 to 2004.
"The fact that it's in Japan means it's a little bit in neutral territory. It's going to be great.
"Ireland have beaten New Zealand in last year.
"Wales are obviously number one at the moment and then there's South Africa and England."
Fellow former All Black Anthony Tuitavake, also coaching this week in northern Italy, added: "I think it's going to be very close.
"Japan had a big win over South Africa last time (2015 World Cup) so hopefully there's going to be some more upsets."