As Australia's only reigning track and field world champion, Barber is among a select handful to have been pre-selected in the Tokyo Games team.

But while there's no pressure from a qualifying perspective, the Canberra-based star acknowledges it's time to start throwing big again with the Olympic opening ceremony less than 100 days away.

After deciding not to travel overseas due to COVID-19 restrictions, the 29-year-old went 16 months between competitions after winning the 2019 world title in dramatic style with a massive final throw of 67.70m in Doha.

Barber has yet to better the 58m mark in a handful of meets so far this year, leaving her well adrift of 2021 world leader Lyu Huihui from China (66.55m) and a host of other throwers including Australia's 2018 Commonwealth champion Kathryn Mitchell (63.49m).

"It's been a rough couple of months for me," said Barber.

"I just lost my mojo a little bit on the throw and I've been trying to work myself into some of my best form.

"It's been a challenge and a place I haven't been before and (coach and husband) Mike (Barber) and I and the team around me have had some new hurdles to overcome.

"It's not been a particular injury, more a few niggles that have unravelled a little bit.

"A big part of it has been learning to come back out again after my world championships win and deal with the level of expectation I have on myself."

Barber was encouraged by a really good training session earlier this week, but she won't target any specific mark in Saturday's final at Sydney Olympic Park.

"We'll step away from numbers a little bit," she told AAP.

"We know what the other girls are throwing, so I'm certainly not blind to knowing what I need to do to win this championship.

"But my best throws come when I'm in a sound place with my process.

"If I can be in a position where I'm standing at the top of the runway, I want to come charging in and be big at the front and whip the javelin out of my hand, then I'm confident my throws will be over 60 metres.

"This weekend will be part of that process."

Australian Associated Press