Billie Jean King, shown here in 2009, will help lead the United States delegation in the opening ceremonies at the Sochi Olympics in Russia, which recently passed an anti-gay law. (Alex Brandon/Associated Press)

Tennis history will record that Billie Jean King won 39 Grand Slam titles during her career. But her life’s work has been equality.

And at 70, King is still on the job, preparing for an assignment that’s a logical extension of that calling: serving as a member of the official U.S. delegation to the 2014 Sochi Olympics.

King is uncommonly qualified for the task. She’s a former world-class athlete; a two-time Olympian, serving as captain of the U.S. team at the 1996 Atlanta and 2000 Sydney Games; and a veteran of multiple trips to Russia that date back to 1962, when she and other top American teens were dispatched for a series of exhibitions behind the Iron Curtain.

King is also openly gay. As such, her role is intended, and expected, to make a strong statement about the Obama administration’s support of the principle of inclusion and its disapproval of Russia’s anti-gay legislation.

It is a role King says she is humbled and honored to play.

“I think our presence is really important,” King said. “I take this very seriously. The responsibility to stand and possibly speak for those who don’t have a voice runs deep.”

King is one of three openly gay athletes among the delegation, along with two-time U.S. hockey medalist Caitlin Cahow and 1988 Olympic figure skating champion Brian Boitano, who chose to publicly acknowledge his sexual orientation after being tapped for the role.

In a telephone interview Thursday, King spoke about her pride in the U.S. Olympic Committee’s support of diversity and inclusion and her hope that the International Olympic Committee, in time, will add “sexual orientation” to the list of attributes safeguarded by Olympic Charter.

King said she is eager to stand in support of those values in Sochi. She’s also eager for the term “openly gay” to be rendered obsolete because society deems it no more relevant than someone proclaiming themselves “openly straight.”

King said she plans to take part in the Feb. 7 opening ceremonies and watch some of the figure skating and hockey competition during her three-day stay in Sochi.

Reared in a sports-minded household with a brother, Randy Moffitt, who played major league baseball, King is an enthusiastic fan of all sports and, of late, has come to particularly admire U.S. figure skater Ashley Wagner and skier Bode Miller for their strong, eloquent public statements in support of equality and in opposition to the Russian law.

That said, King said she empathizes with Olympic athletes who fear their achievements may be overshadowed by a political maelstrom.

“This is first and foremost about the athletes,” King said. “They have trained so long. This could be their moment, their time to shine, to represent their country and be in the Olympic Village and meet other athletes and hopefully win some medals. It’s a lot of pressure, and I hope we don’t lose sight of that.”

King was never the most physically imposing tennis player of her day, nor was she its most naturally gifted. But she was a fierce competitor who thrived under pressure and followed the maxim that “98 percent of winning is showing up.”

“What I mean by that,” King added, “isn’t that you don’t just show up, but you show up and truly embrace the moment emotionally, and in every way.”

So when the State Department called to ask if she would serve on the Sochi delegation, King didn’t hesitate. She promised to show up.

“I believe that it always helps when people come together and build relationships,” King said. “Sports is a universal language. It’s a way to cross borders.”