"The Black Stacks will remain our very best sport stackers competing at the world championships," said the release on NZ Blackstacks website.
"This [junior] team will be a development-type team, those on the cusp of Top 10 world placings."
Anthony, 13, and Millar, 12, are not just in the company of young competitors the "junior" label refers to the next tier and the teenagers have earned their way into the New Zealand squad against stackers of all ages.
They have practised, practised and practised some more to reach their present speeds. "For us, school was just asking if anyone wanted to learn and we put our names down," said Anthony.
"That was four years ago. We've probably done about 20 competitions," Millar added.
The girls have competed many times in Wellington and Palmerston North, where the recent national championships were held.
"At the end of the day they looked at the times, and they placed you with how you did in the world," said Millar.
The Asian championships would "basically be a world" event, serving as a warm-up before the world championships in Seoul, where the main Black Stacks team will compete.
Although they don't know what the junior uniform looks like, they hope it will be a similar to the Black Stacks outfit black with white stripes down one side with the logo on the chest.
Millar said they would be proud to wear the shirt and it looked great "compared to the Australians".
At tournaments, stackers compete with three turns to get their fastest time in three events.
The first is "cycle" where they must take 12 cups up into a pyramid and put them back down again.
Next is a 3-3-3 cup formation of pyramids, taken up and down, followed by 3-6-3 combination.
The cups must be moved in a specific order as quickly as possible with no mistakes.
"It's all eye and hand co-ordination," said Anthony.
Her fastest time on the cycle is 8.865 seconds, while Millar can do it in 8.923.
The pair come from athletic backgrounds, which has no doubt helped them.
Millar has done Saturday sports such as soccer to representative level, as well as basketball and kayaking.
Anthony plays netball and basketball and does gymnastics all year round.
The public can marvel at the girls' speed themselves as they will be putting on a cup stack-a-thon outside The Warehouse in Trafalgar Square tomorrow.
They will be putting on the demonstration from 10am to 4pm and are accepting donations to help in the fundraising towards heading to Taiwan.