Australian swimming's rising star Ariarne Titmus is poised to pull out of the event in which she is considered the best chance of upsetting American great Katie Ledecky at next week's Pan Pacs in Tokyo.
Dolphins head coach Jacco Verhaeren said Titmus had yet to decide whether she would contest the 200m freestyle at the August 9-12 meet.
However, Verhaeren claimed the teenager's Pan Pacs focus would be the 4x200m relay plus distance events.
"We haven't said yes or no to an individual 200m swim. That will be a last-day decision," he said.
"And there are more athletes than just Katie Ledecky to race.
"Katie is a legend and very fast but there are other athletes to deal with as well."
Titmus, 17, is set to line up against world-record holder Ledecky in the 400m and 800m freestyle at the Pan Pacs, a major international meet for non-European nations.
But it was their 200m showdown that was the most anticipated.
Olympic champion Ledecky appeared vulnerable over the shorter distance after being relegated to a shock 200m silver at the 2017 world titles.
The 21-year-old Ledecky boasts the fastest 200m time of the year but it is just 0.29 of a second ahead of Titmus.
"She's focusing a little bit more on the longer distance at the moment," Verhaeren said of Titmus.
"That's long-term planning. It's definitely her (long-term) aim (to race Ledecky over 200m)."
Tasmanian native Titmus has made Ledecky look over her shoulder after taking more than three seconds off her best times in the 200m, 400m and 800m since the 2017 world titles.
She became the first Australian woman to claim the 400m-800m Commonwealth freestyle double since Tracey Wickham in 1982 at April's Gold Coast Games.
However, Titmus is still two seconds slower than Ledecky in the 400m this year and a whopping 12 seconds behind the American in the 800m.
Ledecky has never lost to a younger swimmer at a major international meet final.
The five-time Olympic gold medallist warmed up for the Pan Pacs by clinching three titles - 200m, 400m, 800m - at the five-day US swimming trials which concluded at Irvine, California on Monday (AEDT).
Meanwhile, Titmus and the Dolphins team have arrived for a week-long camp in Nagaoka, Japan ahead of the five-day Pan Pacs in Tokyo.