Coach Cheryl Reeve admitted Wednesday the fate of "gentle soul" Brittney Griner was weighing heavily on the USA team at the basketball World Cup in Sydney and the jailed star's number 15 jersey would not be worn at the tournament.

Griner, a standout when they won gold at the Tokyo Olympics last year, would normally be with the squad as they attempt to claim a fourth straight title and 11th overall, starting Thursday against Belgium.

But the 31-year-old is instead in a Russian prison, sentenced to nine years in a penal colony after being arrested at a Moscow airport in February for possessing vape cartridges with a small amount of cannabis oil.

Reeve said Griner would be "top of mind" throughout the 10-day tournament, and revealed players had been in touch with her to send messages of support.

"The mindset is just trying to stay strong for her and doing what we can," Reeve said, describing Griner as "a gentle soul, just full of love".

She added that players had been able to communicate with their teammate via email, sending "messages of love and support and strength".

"It's on their minds every day. It's heavy, it is really, really heavy especially as we participate in this USA basketball competition," she added.

"She's such a big part of many of our lives, so it's challenging."

No USA team member will don Griner's number 15 jersey in Sydney.

"To keep Brittney top of mind, no one will wear the number 15. That will be the first way to honor her and keep her in our thoughts," said Reeve.

Release talks

US President Joe Biden met Griner's wife, Cherelle Griner, last week as top officials work to bring the player home, with Moscow saying last month it was ready to discuss a prisoner swap.

A White House statement released afterwards did not include details about the status of talks with Russia, but National Security Council spokesman John Kirby said "discussions are ongoing" to secure Griner's release.

"People are hard at work and I think the biggest thing is that we know it's top of mind for many, many people that are a part of this process and they're working very, very hard to try and get Brittney home," said Reeve.

When she was arrested, the two-time Olympic gold medallist and Women's NBA champion had been in Russia to play for the professional Yekaterinburg team, during her off-season from the Phoenix Mercury.

She pleaded guilty to the charges, but said she did not intend to break the law or use the banned substance in Russia.

Griner had testified that she had permission from a US doctor to use medicinal cannabis to relieve pain from her many injuries, and had never failed a drug test. The use of medical marijuana is not allowed in Russia.

Breanna Stewart, the Most Valuable Player at the last World Cup, said that winning another title would be the best way to honour Griner and keep her in the conversation.

"While we're waiting for her to come home, one of the biggest things we can do is win a gold medal for her while we're here and keep her at the forefront of everything we do," said the Seattle Storm star on the same call.

"It's more than what's just happening in these 10 days, it's continuing the momentum that we have to always make sure she is in the spotlight until she's home. We miss her."

© Agence France-Presse