Brittney Griner, the W.N.B.A. star who has been detained in Russia on drug charges since February, sent a handwritten letter to President Biden on Monday asking him not to forget about her.

“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 said in an excerpt from the letter shared by her representatives.

She continued: “I realize you are…