Coco Gauff delivered a speech in support of the Black Lives Matter protests when she spoke at a demonstration in Delray Beach, Florida.
The 16-year-old tennis player emerged earlier in the year as a credible prospect to be the next dominant player of the women's game.
The sport is currently suspended due to the coronavirus, and Gauff attended a protest to explain her thoughts on the Black Lives Matter cause, and to encourage further participation to bring about change.
"I think it's sad that I'm protesting the same thing she (her Grandma) did 50-plus years ago," Gauff began.
Watch Coco Gauff's speech about George's Floyd death
"I'm here to tell you guys this. We must first love each other no matter what. We must have tough conversations with friends.
"I've been having tough conversations all week, trying to educate my non-black friends on how they can help the movement.
"Second, we need to take action. We're all out here protesting and I'm not of age to vote but it's in your hands to vote for my future, my brother's future and your future. So that's one way to make change.
"Third, you need to use your voice, no matter how big or small your platform is. I saw a Dr King quote: 'The silence of the good people is worse than the brutality of the bad people.'
"You need to not be silent. If you are choosing to be silent you are choosing the side of the oppressor.
"I heard many things this past week, and one of the things I heard is, "Well, it's not my problem." If you listen to black music, if you like black culture, if you have black friends, then this is your fight too.
"It's not your job, it's not your duty, to open your mouth to say, 'Lil Uzi Vert is my favourite artist but I don't care what happened to George Floyd. How does that make sense?
"I demand change now. It is sad that it takes another black man's life from us for all of this to happen, but understand this has been going on for years. This is not just about George Floyd. It's about Trayvon Martin, this is about Eric Garner, this is about Breonna Taylor.
"I was eight years old when Trayvon Martin was killed, so why I am here at 16 still demanding change? It breaks my heart. I'm fighting for the future for my brothers. I'm fighting for the future of my future kids. I'm fighting for the future of my future grandchildren.
"We must change now, and I promise to always use my platform to spread vital information."
Highlights: See how 15-year-old sensation Gauff knocked out defending champ Osaka