"But the aim of the game is still to win four matches and play well."
Australia's squad is almost the same one that won the World T20 tournament in Sri Lanka in October.
Injured bowler Julie Hunter has been replaced by Sharon Millanta, with Lauren Ebsary the one player dropped for the Rose Bowl series in which Australia will operate with a squad of 13, one less than at the World T20.
Second-ranked Australia have traditionally held the whip hand in the Rose Bowl, which is usually contested after Christmas but was brought forward this season because of the World Cup.
They have won 20 of the previous 25 series, with world No4 New Zealand triumphant on just three occasions, with the other two drawn.
While Australia and England have been the major powers in women's cricket in recent times, Fields said New Zealand were very competitive and strong.
"They are still a really talented side and we won't be taking them lightly in the next four games," Fields said.
"Being the holders of the Rose Bowl at the moment, there's probably a little bit of pressure on us to retain that, but we've got the right squad and I know most of the girls are playing pretty well at the moment."
- AAP