New Zealand's rugby team All Blacks' coach Steve Hansen dismissed concerns about losing their number one world ranking on Sunday as he concentrated on a World Cup selection conundrum after demolishing Australia.

Despite scoring five unanswered tries to retain the Bledisloe Cup with a 36-0 romp in Auckland on Saturday, the All Blacks lost the top ranking for the first time in 10 years, replaced by Wales courtesy of their 13-6 win against England in Cardiff.

But Hansen said it was the World Cup and not world rankings that mattered and the way his reshaped side bounced back from losing to Australia the previous week raised several questions to be answered before finalising a 31-man squad in 10 days.

“I've never understood their [ranking] system. You win a game and you lose the top ranking,” Hansen said while spelling out the All Blacks' priority.

“We just need to get ourselves in the right frame of mind to go to the World Cup and win that.”

After the 47-26 hiding by the Wallabies in Perth last week, Hansen's decision to axe three established players — Ben Smith, Rieko Ioane and Owen Franks — produced eye-catching performances from their raw replacements Sevu Reece, George Bridge and Nepo Laulala.

As the All Blacks pummelled the Wallabies across the park, Hansen said several players put their hand up for a ticket to Tokyo.

“Where we had question marks we no longer have questions marks, but in other ways it makes it tougher too,” Hansen said listing tighthead prop, the midfield and outside backs and whether to take an extra six or an extra lock as key issues.

Bridge and Reece were particularly prominent with Hansen saying that put pressure on the other wing contenders.

“There's an old saying 'never give a sucker an even break because he'll take it'. Now we've got some genuine competition and it will be good to see how it unfolds.”

Hansen confirmed the shoulder injury that saw Richie Mo'unga leave the field was not serious, and injured lock Brodie Retallick remained in the frame to make the Cup squad.

However, he had no word on whether strongman Liam Squire would change his mind after the blindside flanker asked not to be considered for the World Cup for undisclosed reasons.