Originally Published: 14 JUL 22 02:06 ET

Updated: 14 JUL 22 10:33 ET

By Amir Vera, CNN

(CNN) -- WNBA star Brittney Griner's hearing in a court outside Moscow ended Thursday without a verdict, and a fourth hearing in her trial was scheduled for Friday morning, a US official familiar with the matter said.

Griner appeared a week after pleading guilty to drug charges. The US State Department has said she is being wrongfully detained. Details of Thursday's hearing were not immediately available, but her legal team was expected to request leniency as she faces a sentence of up to 10 years in prison. Her defense was also expected to present character witnesses, the US official said.

Elizabeth Rood, chargé d'affaires of the US Embassy, attended the hearing.

The two-time US Olympics basketball gold medalist was arrested February 17 at a Moscow airport, a week before Russia invaded Ukraine. Russian authorities claimed she had cannabis oil in her luggage and accused her of smuggling significant amounts of a narcotic substance.

Thursday's hearing came as many in the WNBA, along with other athletes, coaches and politicians, have called for Griner's release over fears she is being used as a political pawn amid the war in Ukraine.

Griner wrote a letter to President Joe Biden, saying she fears she will be detained in Russia indefinitely.

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

Griner admitted guilt at her last hearing but told the court that she had not intended to commit a crime, state news agency RIA Novosti reported.

Griner's lawyers hope the court will take into account the 31-year-old athlete's guilty plea, Alexander Boykov and Maria Blagovolina told journalists last week.

Samples taken from Griner did not show any traces of drugs, Boykov added: "She was clean, and she was tested."

It was Griner's decision to plead guilty, her legal team said, adding that she "sets an example of being brave."

"She decided to take full responsibility for her actions as she knows that she is a role model for many people," their statement read.

"Considering the nature of her case, the insignificant amount of the substance and BG's personality and history of positive contributions to global and Russian sport, the defense hopes that the plea will be considered by the court as a mitigating factor and there will be no severe sentence."

Griner is one of the most decorated players in basketball. In addition to her Olympic gold medals, she has won two world championships, a WNBA championship and an NCAA championship. She has twice been crowned the WNBA's scoring champ and the league's defensive player of the year, and was voted onto seven all-star teams before her detention. She was named an honorary all-star in this year's contest earlier this month.