Australia dives into do-or-die Olympic swimming trials at Adelaide on Saturday with question marks swirling around the form of some top names and shock waves reverberating over the withdrawal of dual silver-medallist Maddie Groves.

Swimming has long been the medal-winning backbone of the country, which claimed 10 in the pool at the 2016 Games in Rio, matching its feat from London four years earlier.

But those performances were down on the 20 won at Beijing in 2008 and hopes are high the team can edge back towards those lofty heights in Japan next month.

One swimmer who will not be competing is Groves, a two-time silver medallist at Rio, who pulled out this week blaming "misogynistic perverts in sport and their bootlickers".

The target of her comments was not clear and Swimming Australia said it had not received any official complaints.

"We haven't been able to talk to her directly and go through her concerns to find out what's going on," SA president Kieren Perkins said on Friday.

As for matters in the pool, SA has set the bar high at the six-day trials - to qualify, athletes must match or better the time needed to make the final at the 2019 world championships.

Head coach Rohan Taylor said he had been impressed so far.

"The past 12 months and the lead up to the Australian swimming trials has no doubt been a challenging time for our swimmers and coaches, but I'm proud of the way they have learnt to adapt and gain yet another level of resilience," he said.

"What is most pleasing, is that even though the athletes have had to overcome these hurdles along the way, we've seen solid performances and times at recent events."

After months of gruelling work, with swimmers tapered and so much on the line, world records could tumble, with teenager Kaylee McKeown at the forefront.

She swam the second-fastest women's 100-metre backstroke ever (57.63 seconds) last month to narrowly miss American rival Regan Smith's world record.

She will be eyeing a new mark on Sunday and will also contest the 200m back, having recently set the fourth quickest time in history.

The 19-year-old also owns the world's best time this season in the 200m individual medley.

Versatile Emma McKeon, who won four medals in Rio, is another in form, boasting the year's fastest women's 100m freestyle time as she prepares for battle with sprint queen Cate Campbell, who is gunning for a fourth Olympics.

But some big names have their work cut out, notably defending Olympic 400m champion Mack Horton.

He was 35th in the 200m at the national championships in April and pulled out of the 400m, with rising stars Elijah Winnington and Thomas Neill - as well as proven distance ace Jack McLoughlin - snapping at his heels.

"It's not really reflective of what I can do in training," Horton, who will swim the 400m on Saturday, insisted recently.

Women's world 400m freestyle champion Ariarne Titmus, who is eying a Tokyo showdown with American great Katie Ledecky, will be in action Sunday as she looks to prove she is fully recovered from a shoulder injury. Titmus will also swim the 200m and 800m.

Defending Olympic 100m freestyle champion Kyle Chalmers swims his pet race on Tuesday, while former pop star Cody Simpson - who once dated Miley Cyrus - will also be in action.

But the 24-year-old, a talented junior swimmer who returned to the sport in 2019, would have to shatter his personal best by a wide margin in the 100m butterfly to make the plane to Japan.

Source: News24