Griner "is now on her way to a penal colony," lawyers Maria Blagovolina and Alexander Boykov said in a statement, per CBS News.
"We do not have any information on her exact current location or her final destination," the attorneys added, noting that if Russia follows standard procedure they should be notified when Griner reaches her destination by mail, which could take two weeks.
In a statement amid the transfer, White House press secretary Karine Jean-Pierre reiterated the "substantial offer" that the U.S. had put on the table to secure Griner's release.
"Every minute that Brittney Griner must endure wrongful detention in Russia is a minute too long," Jean-Pierre said. "As the administration continues to work tirelessly to secure her release, the president has directed the administration to prevail on her Russian captors to improve her treatment and the conditions she may be forced to endure in a penal colony."
The WNBA star was first detained in Russia on February 17, when authorities found cannabis oil in her bag at a Moscow airport. She plead guilty to drug charges after admitting she "inadvertently" brought cannabis into the country and was sentenced to nine years in a Russian prison, which falls just below the 10-year maximum.
Griner and her legal team appealed the sentence, which was denied in a Russian court last month.
Lawyers for the Phoenix Mercury guard said her transfer to one of Russia's penal colonies, which are known to have much harsher conditions than the Moscow jail she was previously detained in, began Friday (November 4).
Secretary of State Antony Blinken, who first announced in July the "substantial" proposal to free Griner, slammed Russia's move to transfer Griner "to a remote penal colony," saying it was "another injustice layered on her ongoing unjust and wrongful detention" in a statement on Wednesday (November 9).