Amid Griner's ongoing trial in Russia, the Phoenix Mercury guard admitted to having cannabis oil in her possession at the time of her detainment.
However, Griner said that she didn't intend to break Russian law as the substance was accidentally packed in her luggage.
"I'd like to plead guilty, your honor. But there was no intent. I didn't want to break the law," Griner said as she submitted her guilty plea on Thursday.
Griner was first detained on February 17 when authorities allegedly found hashish oil, a substance derived from cannabis, in her bag at a Russian airport.
The Russian detainee's guilty plea comes on the second day of her trial in Khimki, Russia. According to ESPN, the trial could still go on for weeks or months despite the move to plead guilty as the judge is expected to go through her case file in full.
U.S. officials previously said a guilty verdict was a foregone conclusion, describing the Russian trial as merely "theatre."
Russian experts have agreed stating that a guilty plea was Griner's best path to being released, regardless of the facts.
Resolution for the case is expected to come from a deal that would send a number of Russians currently in U.S. custody back to their country in exchange for the WNBA player's release.
An ESPN source said the plea was an effort to bring Griner home as soon as possible and the basketball star would deal with the repercussions of pleading guilty when she makes it back into the country.