Mike Hussey admitted Australia's confidence had been dented after they suffered a third straight one-day loss.
The Aussies have lost four of their last five one-day internationals
The world champions were thrashed by 10 wickets in the opening Chappell-Hadlee Trophy game against New Zealand after being bundled out for a paltry 148.
It was their fourth defeat in five ODIs and stand-in skipper Hussey said: "It's not a nice feeling. It's a demoralising loss and probably as low as we've been.
"Everything seemed to go the wrong way and it can only go up from here."
Australia have now lost four of their last five one-day internationals after three defeats by England at the back end of the Commonwealth Bank Series.
"We've got a new group at the moment and we've just got to mould together as quickly as possible," Hussey added.
Regular captain Ricky Ponting and wicket-keeper Adam Gilchrist have been rested for the New Zealand matches.
They had the worst of the pitch, it got better for us and we rode our luck
Key all-rounder Andrew Symonds is not expected to recover from shoulder surgery until the latter stages of the forthcoming World Cup.
Paceman Brett Lee is now a doubt for the tournament in the Caribbean after suffering an ankle injury, while batsman Michael Clarke has returned home with a sore hip.
Without those star names, the Aussies failed in testing batting conditions, with Shane Bond taking 5-23.
Lou Vincent (73no) and Kiwi skipper Stephen Fleming (70no) then knocked off the required runs in only 27 overs.
"Everything for them went wrong and everything for us went right, right from the toss," Fleming said. "They had the worst of the pitch, it got better for us and we rode our luck.
"It's the best I've seen Shane bowl for some time and not just because he got five wickets. His control was outstanding, and his thought processes were great."