US tennis great Serena Williams announced on Tuesday that "the countdown has begun" to her retirement from the sport.
Williams, 40, won the last of her 23 Slams at the 2017 Australian Open when she was already pregnant with daughter, Olympia.
However, she has failed to add a 24th major which would take her level with Margaret Court's all-time record.
Her final attempt will come at the US Open in New York later this month.
"There comes a time in life when we have to decide to move in a different direction," she said on Instagram.
"That time is always hard when you love something so much. My goodness do I enjoy tennis. But now, the countdown has begun.
"I have to focus on being a mom, my spiritual goals and finally discovering a different, but just exciting Serena. I'm gonna relish these next few weeks."
Williams stepped onto a hardcourt for the first time in a year and a half on Monday in the WTA Toronto tournament where she reached the second round with a straight sets victory over Spaniard Nuria Parrizas Diaz.
It was her first singles victory since the 2021 French Open, 14 months ago.
The former world number one had played her first singles match in a year following a lengthy injury layoff during a first round defeat at Wimbledon in June.
Earlier on Tuesday, Williams wrote in the September edition of Vogue magazine where she featured on the cover that she was "evolving away" from the sport after the US Open.
"Unfortunately I wasn't ready to win Wimbledon this year," she said in the publication.
"And I don't know if I will be ready to win New York. But I'm going to try. And the lead-up tournaments will be fun. I know there's a fan fantasy that I might have tied Margaret that day in London, then maybe beat her record in New York, and then at the trophy ceremony say, 'See ya!' I get that. It's a good fantasy.
"But I'm not looking for some ceremonial, final on-court moment. I'm terrible at goodbyes, the world's worst."
Williams won her first Grand Slam title at the 1999 US Open, when she was 17.
She has won the Wimbledon and Australian Open singles title seven times each, along with six US Open trophies and three French Open successes.
"I have never liked the word retirement. It doesn't feel like a modern word to me," she said.
"I've been thinking of this as a transition, but I want to be sensitive about how I use that word, which means something very specific and important to a community of people. Maybe the best word to describe what I'm up to is evolution.
"I'm here to tell you that I'm evolving away from tennis, toward other things that are important to me.
"A few years ago I quietly started Serena Ventures, a venture capital firm. Soon after that, I started a family. I want to grow that family.
"But I've been reluctant to admit to myself or anyone else that I have to move on from playing tennis. Alexis, my husband, and I have hardly talked about it; it's like a taboo topic.
"In the last year, Alexis and I have been trying to have another child, and we recently got some information from my doctor that put my mind at ease and made me feel that whenever we're ready, we can add to our family. I definitely don't want to be pregnant again as an athlete. I need to be two feet into tennis or two feet out."