American teenage tennis star Coco Gauff can help "change the world for the better"," says 18-time Grand Slam champion Martina Navratilova.
The 16-year-old has repeatedly spoken to demand social change following the death of George Floyd.
At a peaceful protest in Florida last month, Gauff urged people to vote and speak out against racism.
"I smile so much when I see the reach she already has now, and she will have in the future," said Navratilova.
She told BBC Radio 4's Today Programme: "She is just so poised on and off the court, she was brought up with great qualities and it shows how she plays and it shows how she's active now politically.
"She's one of those people that can change the world for the better, and she seems to want to do that."
Navratilova, 63, says it is "essential" sport stars use their platforms as they can see "how much politics can affect their lives and their freedoms".
"Sport has always been at the forefront of social change," she added. "And now it can be that again with Black Lives Matter and just equality for all.
"Tennis has had its share of obstacles, but I think overall, we've been at the forefront of social change and it seems like now with Coco Gauff, leading the charge, we're still there."
It is also time for tennis to unite, Navratilova added, as she explained why it was time for the men's ATP and women's WTA tours to merge.
It is something she and Billie-Jean King have been talking about since the 1980s but which has been discussed again in recent months after Roger Federer said in April that "now is the time".
Speaking to Thursday's edition of BBC Two's Wimbledon: The Best of the Championships, she said a united front would make it easier to tackle issues such as the four Grand Slam events each having different rules for deciding the final sets of matches.
"The only way to put the pressure on the ITF and on the majors is if men and women are together," she said. "We should have the same rules for men and women - how much time between points, how you play the matches, coaching etc.
"It just doesn't make sense that women do it that way and men do it that way, it's the same sport, the same size tennis court and the same balls."
In a wide-ranging interview, she also said the interruption to the tennis year because of the coronavirus pandemic had come at the wrong time for American 38-year-old Serena Williams, who is still chasing a 24th Grand Slam singles title to draw level with Margaret Court's all-time record.
"Time is not her friend. Yes, she gets to rest but the body is still aging even though she's resting. I think emotionally it would be really hard to stay motivated and keep your routine," she said.
"But I know she's still fired up, she wants that record, she's been going after it for a while now."