After watching Olympic champion Bruce Jenner declare himself a transgender woman during a nationally televised interview last month, Billie Jean King realized her next ophthalmologist visit was going to be a long one.

King's ophthalmologist is Renee Richards, the tennis player who in 1975 underwent a sex-change operation to become a woman.

"We'll be having a lengthy discussion about it, I can guarantee you that," said King, 71, who became one of the first openly gay sports superstars following a 1981 lawsuit by a former lover. "I probably ought to take her out to dinner."

King was in Philadelphia Tuesday to commemorate the 40th season of World TeamTennis and the Philadelphia Freedoms, a franchise she owns. Mayor Nutter has proclaimed Wednesday Philadelphia Freedoms Day.

While the issue of sports and sexuality remains a sensitive one, King said she was encouraged by the mostly positive reaction to Jenner's disclosure. When she was outed, the blowback was fierce. She lost endorsements. Some events rescinded invitations. And ultimately, she lost a marriage.

"We need these blasts every so often for people to return to the dialogue," King said. "It's a healthy discussion to be having. There's still a lot of discrimination for a lot of us, but [the younger generations], their take on the world is so different than ours. They cannot believe we even care about these things. And that's encouraging.

"I know Bruce and you could see how tormented he's been throughout his life," she said. "I know how tough it was for me in '81. It was terrible. I lost everything overnight. That won't happen today and that makes me happy."

King was also a pioneer in World TeamTennis, a concept she helped popularize as a member of the Freedoms in the mid-'70s. Founded in 1974, the league has seen its popularity ebb and flow over the years - it was idle in 1979 and 1980. Originally a 16-team league, it is now down to seven.

The challenge, said King, has been finding enough time for the best players in the world to compete. Because tournament tennis has become a year-round sport, the league's entire 2015 schedule had to be compacted into 21/2 summer weeks.

"As time went on, tennis has become much more popular globally and its calendar has become tighter and tighter," King said.

The Freedoms, for example, will play all seven of their home matches at Villanova's Pavilion from July 16 through July 28.

"That's a problem everyone in tennis, every event, faces," she said. "But we've survived 40 seasons and I think that puts us in a pretty unique spot when it comes to team sports."

What has helped keep the WTT going that long, King believes, is that it remains the only significant team sport in which players of both genders compete together.

"That's been great," she said. "It's such a learning experience for kids to see men and women working together, whether it be in the family, in school or in sports. That's the way I want the world to look."

Whatever its appeal among average sports fans, the format has no bigger supporter than its former commissioner. Each WTT match consists of five sets, and each set is a different discipline - singles and doubles for men and women as well as mixed doubles.

"I went to every match last year, home and away," King said, "and it's the most fun I've ever had, whether as a player, owner, I don't care. I've felt from the beginning that the team concept is the way to grow our sports. Americans love team sports and you don't have to be a fan of tennis to cheer for your home team."