American basketball star Brittney Griner has returned to Russian court for the third hearing in her trial on drugs charges for which she could face up to a decade in prison. 

    Griner was seen wearing her jail scrubs as she was escorted to her hearing at Khimki Court in Moscow on Thursday. Her attorneys Maria Blagovolina and Alexander Boykov were also spotted walking into court on Thursday. 

    In Russia, a guilty plea doesn't mean that the trial is automatically over. Griner's defense may put forward arguments during the hearing to mitigate the punishment, or a verdict could be announced. But it wasn't immediately clear what would happen at the hearing. 

    With the U.S. government under pressure at home to do more to secure her freedom, the guilty plea could be an effort to expedite the court proceedings so any negotiations could move forward. 

    A senior Russian diplomat has said no action could be taken by Moscow until the trial was over.

    The Phoenix Mercury center and WNBA all-star was detained at Moscow´s Sheremetyevo Airport in February while returning to play basketball in Russia. 

    Police said they found vape canisters containing cannabis oil in her luggage. 

    Griner, 31, who  has been custody since then, faces charges that could bring her a sentence of up to 10 years in prison.

    The news comes amid reports Griner could be swapped for Russian arms dealer Viktor Bout, convicted in 2011 and known as the 'Merchant of Death' to US officials.

    Nicolas Cage's character in 'Lord of War' was inspired by Bout, with the Hollywood actor going by the pseudonym Yuri Orlov in the film. 

    Bout was dubbed the 'Merchant of Death' because of his rise to the top of international arms trafficking.

    He is serving his sentence in the United States Penitentiary in Marion, Illinois, and has five years left in prison.

    Shira A. Scheindlin, the former New York City federal judge who sentenced Bout before returning to private law practice, can be counted among those who would not be disappointed by Bout's freedom in a prisoner exchange.

    'He´s done enough time for what he did in this case,' Scheindlin said in an interview, noting that Bout, a vegetarian and classical music fan who is said to speak six languages, has served over 11 years in U.S. prisons.

    Now held in a medium-security facility in Marion, Illinois, Bout is scheduled to be released in August 2029.

    'The idea of trading him shouldn´t be unacceptable to our government. It wouldn´t be wrong to release him,' Scheindlin said.

    Griner has been in custody since she was arrested in February while returning to play basketball in Russia. She pled guilty last week to carrying vape cartridges containing hashish oil, but said she did not intend to break the law.

    Griner's lawyer said her trial could now last up to two months, echoing what a US official told Politico last week.

    In pleading guilty during the previous court hearing on July 7, Griner said she had no intention of committing a crime and had acted unintentionally because she packed for Moscow in a hurry.

    US President Joe Biden and secretary of state Antony Blinken said they were doing all they could to win the release of Griner, as well as other Americans the US considers 'wrongly detained' by Russia, including former marine Paul Whelan.

    Earlier this week, Griner wrote a letter to Biden to in which she pleaded with him to help secure her release. 

    'As I sit here in a Russian prison, alone with my thoughts and without the protection of my wife, family, friends, Olympic jersey, or any accomplishments, I'm terrified I might be here forever,' Griner wrote in the letter. 

    'I realize you are dealing with so much, but please don't forget about me and the other American Detainees,' Griner wrote. 'Please do all you can to bring us home. I voted for the first time in 2020 and I voted for you.

    'I believe in you. I still have so much good to do with my freedom that you can help restore. I miss my wife! I miss my family! I miss my teammates! It kills me to know they are suffering so much right now. I am grateful for whatever you can do at this moment to get me home.' 

    Her letter came after Biden and Harris made a phone call to her wife, Cherelle, to 'reassure her' they are working to get her released.

    'The President called Cherelle to reassure her that he is working to secure Brittney's release as soon as possible, as well as the release of Whelan and other US nationals who are wrongfully detained or held hostage in Russia and around the world,' the White House said.

    Washington may have little leverage with Moscow, though, because of strong animosity over its military operation in Ukraine.

    Russian media have speculated that Griner could be swapped Bout, nicknamed The Merchant Of Death, who is serving a 25-year sentence in the US after being convicted of conspiracy to kill US citizens and providing aid to a terrorist organization.

    Bout, 55, was sentenced to 25 years in prison in 2011 after being convicted of selling arms to Colombian rebels. 

    Russia has agitated for Bout's release for years.

    But the wide discrepancy in the seriousness of their cases could make such a trade unpalatable to Washington.

    Others have suggested that Griner could be traded along with Whelan, who is serving 16 years in Russia on an espionage conviction that the US has described as a setup.

    The State Department's designation of Griner as wrongfully detained moves her case under the supervision of its special presidential envoy for hostage affairs, effectively the government's chief hostage negotiator.

    The classification has irritated Russia.

    Asked about the possibility of Griner being swapped for a Russian jailed in the US, deputy foreign minister Sergei Ryabkov, the senior     Russian diplomat, noted that until her trial is over 'there are no formal or procedural reasons to talk about any further steps'.

    Ryabkov warned that U.S. criticism, including the description of Griner as wrongfully detained and dismissive comments about the Russian judicial system, 'makes it difficult to engage in detailed discussion of any possible exchanges.' 

    Griner's detention has been authorized until December 20, suggesting the trial could last months.

    Griner's lawyers, however, said they expect it to conclude around the beginning of August.