INDIAN WELLS, Calif. (AP) - Serena Williams has withdrawn from the BNP Paribas Open that begins Wednesday because of a left knee injury, leaving the desert tournament without the world's top-ranked women's player.

Williams says in a statement released through the tournament Tuesday that she also won't play the Miami Open, which follows Indian Wells on the circuit.

She says she hasn't been able to train because of her knees and she's disappointed she can't play.

Williams is a two-time winner at Indian Wells, where she returned in 2015 after a lengthy boycott. She reached the semifinals that year and the final last year, where she lost to Victoria Azarenka in straight sets.