(FILES) In this file photo taken on August 04, 2022, US Women's National Basketball Association (WNBA) basketball player Brittney Griner, who was detained at Moscow's Sheremetyevo airport and later charged with illegal possession of cannabis, arrives to a hearing at the Khimki Court, outside Moscow. - Former US diplomat Bill Richardson said on August 7, 2022, that he was "optimistic" about efforts to negotiate a "two for two" prisoner swap with Russia that would free US basketball star Brittney Griner and another American. (Photo by Kirill KUDRYAVTSEV / AFP)

Former US diplomat Bill Richardson has expressed confidence that a prisoner swap can be negotiated with Russia to free basketball player Brittney Griner.

“I’m optimistic,” the former US ambassador to the United Nations said on ABC on Sunday. “I think she will be released. I think she’s pursuing the right strategy with regret.”

Richardson was involved in the release of several US citizens who had been held in other countries. According to media reports in July, he should now also travel to Russia to negotiate Griner’s release.

A Russian court on Thursday sentenced the athlete to nine years in prison for drug trafficking and a fine of one million rubles (around 16,000 euros). On Friday, the Russian government agreed to negotiate a prisoner exchange.

“There will be an exchange of prisoners,” Richardson said confidently in the television interview. Although he emphasized that he was only indirectly involved in possible negotiations, he seemed to be very well informed: Richardson, in his own words, expects a “two for two” prisoner exchange in order to also free the former US soldier Paul Whelan imprisoned in Russia.

According to US media reports, Griner and Whelan could be swapped out for notorious Russian arms dealer Viktor Bout, who is serving a 25-year prison sentence in the US. It is not yet clear who the second Russian could be.

Griner, who plays for the Phoenix Mercury team in the US professional league WNBA and for the Russian team UMMC Yekaterinburg during the season break, was arrested at Moscow’s Sheremetyevo Airport in February – shortly before the start of the Russian war of aggression in Ukraine.

Cartridges for e-cigarettes with cannabis oil were found in their luggage. According to prosecutors, the amount corresponded to less than one gram of cannabis in solid form.