Coach Jacco Verhaeren says Australia will have a "transition year" after Jess Ashwood became the latest to withdraw from July's world swim titles.
Already hit by high-profile withdrawals, Australian coach Jacco Verhaeren admits the national swim team will be in a "transition year" after Jess Ashwood became the latest star to pull out of July's world titles in Budapest.
However, Verhaeren was confident the Dolphins team's future was bright after Ariarne Titmus joined the young guns firing world titles warning shots at the national championships in Brisbane.
Some of Australian swimming's biggest names were missing from the 35-strong Australian squad bound for Hungary after the five-day national titles concluded on Thursday night.
Rio relay silver medallist Ashwood became the latest to pull the pin in a bid to extend her career to 2018 Commonwealth Games and 2020 Tokyo Olympics.
She joined ex-world champions Cate Campbell and James Magnussen, butterflier Maddie Groves, 2016 Games relay silver medallist Tamsin Cook and former 200m freestyle world No.1 Thomas Fraser-Holmes.
Verhaeren admitted no one could replace his growing list of no shows.
"In reality you can't make up for their absence," he said.
"But I am okay with people who withdraw from a team as long as it is backed up with a solid plan that allows them to return.
"And they all had good reasons. It's thinking about the longevity of their careers."
Verhaeren was still excited about the world titles after 16-year-old Titmus provided another reminder of Australia's emerging talent on Thursday.
She claimed the 400m freestyle crown by shattering her personal best by five seconds, adding it to her 800m title in Brisbane.
Titmus looks set to contest the 200m, 400m, 800m and 4x200m relay at Budapest, booking a showdown with Olympic champion Katie Ledecky of the US.
Youngsters Jack Cartwright (100m, 200m freestyle), Matthew Wilson (200m breaststroke), 15-year-old Kaylee McKeown (200m backstroke), Clyde Lewis (200m IM-400m IM) and Shayna Jack (50m freestyle, 4x100m freestyle relay) also shone bright in Brisbane.
"It is a transition year. But we have up and coming talent which we wanted to see because we can't keep relying on the same people every year," Verhaeren said.
"They are not all medal winners but you can't expect that from a young team like this.
"But it's an important step in their career - it's exciting."
Some of Australia's biggest names will still fly the flag at Budapest.
Bronte Campbell will back herself to defend her 50m-100m freestyle world titles in Hungary after completing the domestic double for the first time.
She won the 50m final on Thursday, just 0.03 of a second quicker than her older sister Cate.
Rio champion Mack Horton will also feature in Budapest after claiming 1,500m freestyle gold on Thursday.
He became the first man to claim 200m, 400m and 1,500m national crowns since Grant Hackett in 2008.
Winners of Thursday's other finals were Emma McKeon (200m butterfly), Emily Seebohm (200m individual medley), Ben Treffers (50m backstroke) and Tommy Sucipto (50m breaststroke).