US tennis great Billie Jean King, a high-profile advocate of gender equality, has urged more players to take up causes off court and help "make this world a better place".
King, the 74-year-old former world number one, said famous players have a global platform to speak out on social issues and that she wished more would take up the challenge.
"Our job is to motivate, to inspire and to be leaders off the court as well as on the court and to give back to everyone what we can," she told AFP at a Women's Tennis Association (WTA) finals event in Singapore.
Players should "really do something special off court as well, not just on the court and play great tennis", she said, urging them to ask the question "what can I do to make this world a better place?"
King, who founded the WTA, has used her global fame to speak out on gender equality both within and outside the sport.
She has also campaigned for equal prize money and rights for men and women in the sport.
In 1973, she beat men's former number one Bobby Riggs, a self-proclaimed male chauvinist, in the famous "Battle of the Sexes" match.
"Other people in the world would give anything to have the platform we have so we need to be cognisant and aware of that and... try to make a difference," she said.
King's comments come after Judy Murray, the Scottish tennis coach and mother of Andy and Jamie Murray, urged Serena Williams and other top female players to take the lead in pushing for changes in women's tennis.
- #MenToo -
Speaking on International Women's Day on Thursday, Murray voiced concern that male players are more vocal in advocating change.
"Serena, now that she's had a baby girl, I'm hoping as she comes towards the end of her career that she will use her voice to make things change for women," Murray said.
"It's not all about equal prize money, it's about grassroots opportunities and helping the female game across the world get stronger."
King also said she would like to see men playing best-of-three-set matches at Grand Slam tournaments, an innovation that would bring them them line with women.
Much of the debate over equal prize money for men and women has centred on whether female players provide as much entertainment, given their matches are shorter.
"Personally, I don't want the men playing five sets anymore. I think it takes too much out of them," she said.
"Like one time the players played in the Australian Open final. It took six hours," said King, referring to the epic 2012 decider between Novak Djokovic and Rafael Nadal.
"They could hardly walk off the court. I guarantee you that it took a year off their careers."
King, a vocal supporter of the #MeToo movement, also urged men to take advantage by speaking about sexual abuse.
"The #MeToo campaign has completely helped to allow people who are abused -- not just women, men and women (to speak out). Men, don't forget that, because lots of times they think it's for women," King said.
"It's for anybody who's been abused. Now, you're not alone anymore."
She added: "We need sports, we need every industry to get behind the #MeToo and #TimesUp movements," she added.