The world No. 4's spirits were lifted during her injury hiatus by spending time with children. (AP)

Before she was a French Open finalist, Miami Open winner and US Open champion, Sloane Stephens was in a boot. It was one of those ugly, bulky ones, complete with a peg-leg contraption that helped her walk without bearing weight on her bad foot. 

During her now-famous injury layoff, which lasted 10 months from the 2016 Olympic Games to her comeback match at Wimbledon last year, she says her foundation helped her stay upbeat. 

"When I was injured and no one cared what I was doing and had no interest in me whatsoever," Stephens said in a phone press conference. "I worked on my foundation everyday."

The Sloane Stephens Foundation helps young people build better futures by providing education on healthy lifestyles, nutrition and physical fitness. 

Even when Stephens couldn't put both feet down on the court, she was out helping children discover the sport of tennis. 

"I was playing with kids every day and going to after school programs, and playing tennis on Saturdays with the kids in my foundation," Stephens said. "It's something I really, really enjoy. I love giving back, I love kids and I love giving them the opportunity."

A lot has changed since she had so much spare time on her hands—which she partly spent launching a successful career as a Tennis Channel reporter. That role still involved charitable work, as she became a part of Soles4Souls, a charity collecting shoes for those who need them. 

These days, the foundation is still a big part of her life, even as she's busy climbing the ranks to a career-high of No. 4 in the world. 

"No matter what my priority is always going to be the kids and the foundation," the 25-year-old said. "When I was sad and I was upset that I couldn't play, the kids really put a smile on my face. The time that I was injured, I was able to give my full self to these kids. That really kept me going over the six months that I was at home."

 

Ready for grass court szn ????

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Stephens has put her injury behind her, as she turns her focus on Wimbledon. Though she's back doing what she loves, at the highest level possible, she's not quite the same person anymore—in a good way—and it's thanks to the kids. 

"It really gave me something to look forward to every day," Stephens said. "Without that I probably couldn't be as happy as I am on court right now."