Tennis legend Billie Jean King has announced that she won't attend Friday's opening ceremonies of the Winter Olympics in Sochi.

King was one of the three openly gay athletes chosen by President Barack Obama to represent the United States as part of a 10-person delegation to the Olympics. The other two athletes are hockey player Caitlin Cahow and figure skater Brian Boitano.

King said she would not attend because her 91-year-old mother is ill. Cahow, originally scheduled to attend the closing ceremonies, will take King's place.

King has been an outspoken critic of Russia's law prohibiting “gay propaganda” to minors.

Last month, King applauded Obama's decision to include gay athletes in the delegation, saying it conveys a powerful message to Russia.

“When we step off the plane we are part of America,” King said during an appearance on NBC's TODAY show. “We are what an America looks like. So I think President Obama has done an amazing job on promoting diversity and inclusion. He has been the all-time president for doing that. And he's showing the Russians, 'Listen everybody belongs in the United States of America.'”