Eight days after Brittney Griner pleaded guilty to drug charges, the WNBA star’s attorneys introduced new evidence they hope will result in a more lenient sentence.

Lawyers on Friday presented a Russian court with an American doctor’s letter saying that Griner had been prescribed medical marijuana to help her cope with chronic pain from injuries that she sustained during her basketball career.

[UPDATE: Brittney Griner released from Russian prison 10 months after arrest]

“The attending physician gave Brittney recommendations for the use of medical cannabis. The permission was issued on behalf of the Arizona Department of Health,” lawyer Maria Blagovolina told the Associated Press.

Griner entered the courtroom wearing a tie-dye Nirvana T-shirt and watched the fourth day of her trial from the defendant’s cage directly behind her attorneys. A Reuters photographer captured her holding up a photo of WNBA players all wearing No. 42 jerseys in her honor during the league’s all-star game last weekend.

On Thursday, the Russian court heard testimony from multiple character witnesses from the Russian basketball club that Griner has played for during the WNBA offseason. UMMC Ekaterinburg team captain Evgeniya Belyakova and team director Maksim Ryabkov spoke on Griner’s behalf.

"Brittney has always been a good teammate, which is why my role here is to support her and be there for her," Belyakova, a member of the Russian National team, told reporters outside the courtroom after Thursday’s hearing.

Griner has been behind bars since Feb. 17, when she flew into a Moscow airport and Russian customs officials allegedly found vape cartridges containing less than a gram of cannabis oil in her luggage. Her trial could result in a prison sentence of up to 10 years unless U.S. and Russian officials can negotiate a prisoner exchange that would bring her home sooner.

Yuval Weber, an expert on Russian military and political strategy, told Yahoo Sports that all the doctor’s notes and character witnesses in the world aren’t going to have much impact on Griner’s sentence.

“It might reduce it from 10 years to 9 years,” said Weber, ​​a distinguished fellow at Marine Corps University's Brute Krulak Center for Innovation and Future Warfare.

Weber said he has “zero doubt the judge will not be making an independent decision” on Griner’s fate. The way Weber sees it, Russian government officials will dictate the length of Griner’s sentence — and they lose the upper hand in subsequent negotiations with the U.S. if they show lenience.

“The longer her sentence, the more basic leverage Russia has,” Weber said.

Last week, on the second day of her trial, Griner pleaded guilty to drug charges, stressing that she “did not want to break the law” and that she packed the vape cartridges by mistake. Her guilty plea came after Russian Deputy Foreign Minister Sergei Ryabkov hinted that a deal for Griner’s release was possible but only after the conclusion of her trial.

Griner’s guilty plea was smart strategy, experts in Russian law told Yahoo Sports last week. Not only could it potentially lead to a lighter sentence, most crucially, it also could speed up the trial and accelerate negotiations for Griner’s release.

“The Russians have said they wouldn't really consider a prisoner swap until she has been found guilty, so this expedites that matter,” said William Pomeranz, the acting director of the Wilson Center’s Kennan Institute and an expert in Russian law. “If she wants to return home and she believes they're working on a prisoner swap, the faster that this proceeding ends, the faster she can get home.”

The State Department in May declared Griner to be “wrongfully detained” in Russia, a classification that allows U.S. officials to begin negotiations for her release. Secretary of State Antony Blinken has described securing the freedom of Griner and other wrongly detained Americans as a top priority.

On July 4, Griner sent President Biden a letter urging him to “please don’t forget about me and the other American detainees”

“I’m terrified I might be here forever,” she wrote.

In response, Biden called Griner’s wife, Cherelle, to reassure her that he is working to bring Brittney home as soon as possible. Biden also read Cherelle a letter that was delivered to Brittney the following day.

Griner’s imprisonment comes at a time of renewed hostility and distrust between the U.S. and Russia. Relations between the two nations are at their lowest point since the Cold War as a result of Russia’s assault on Ukraine and the U.S. joining Western allies in imposing economic sanctions.

Efforts to negotiate Griner’s release have also been complicated by Russia’s apparent asking price in a potential prisoner exchange. Russian state media outlets have linked Griner’s case to the fate of notorious Russian arms dealer Viktor Bout, who earned the nickname “Merchant of Death” by allegedly smuggling military-grade weapons to rogue leaders and insurgent groups across Africa and beyond.

In 2008, the DEA successfully baited Bout into flying to Thailand to finalize a deal with federal agents posing as members of a Colombian terrorist group. Bout was extradited to the U.S. in 2010 and is currently serving a 25-year sentence in a federal prison in Illinois for conspiring to sell weapons to people who planned to use them to kill Americans.

The next hearing in Griner's trial is scheduled for July 26. While Griner's detention has been authorized through Dec. 20, her attorneys have previously told reporters they expect her trial to finish by the beginning of August.