Serena Williams has revealed that her coach told her to stop breastfeeding to improve her tennis, saying the advice was "hard to take from a guy".
The tennis champion described how she chose to nurse her daughter for her first eight months - despite believing it was harming her returnto peak physical form.
However, it became a sore point between the player and her coach, Patrick Mouratoglou, who told her tennis would have to be "priority number one" if she wished to be successful.
The player said when she arrived in France for the clay court training earlier this year, Mouratoglou told her she should stop breastfeeding for the sake of her performance.
"It's absolutely hard to take from a guy," Williams told Time Magazine. "He's not a woman, he doesn't understand that connection, that the best time of the day for me was when I tried to feed her.
"You have the power to sustain the life that God gave her. You have the power to make her happy, to calm her. At any other time in your life, you don't have this magical superpower."
The 23-time grand slam winner reached the final at Wimbledon in July less than a year after giving birth her daughter, Alexis Olympia Ohanian, with venture capitalist Alexis Ohanian.
She dedicated her performance to "all the mums out there", coming just 10 months after she suffered life-threatening complications following an emergency caesarean section.
She suffered the worst defeat of her grand slam career when she lost to Britain's Johanna Konta in San Jose, California at the end of the month.
Williams, who has been vocal about her struggle to juggle be a hands-on mother alongside a return to competitive sport, features on an upcoming issue of Time.
"I never understood women before, when they put themselves in second or third place. And it's so easy to do," she said.
Williams also spoke about her struggle to regain her figure after giving birth, saying she "fell victim" to social media pressure.
The tennis star revealed she used a waist trainer to make her stomach appear smaller when she posted a picture of her post-pregnancy body on Instagram.
"I hated that I fell victim to that. It puts a lot of pressure on women," she said.
Williams features on the cover of an upcoming Time Magazine. Photo / Time Magazine
In 2016 Williams removed a picture of her from her Instagram page after more than 600 fans complained that it had been digitally altered to make her waistline slimmer.
Williams quickly replaced the image, from a photoshoot with People Magazine, with a near identical one, albeit with a slightly wider waist.
In the wide-ranging interview Williams also addresses for the first time reports that her sister Yetunde Price's killer has been released from prison.
Robert Maxfield, a gang member, killed Ms Price in a drive-by shooting in Compton, California in 2003. Ms Price a mother-of-three, was just 31 at the time of her death.
Maxfield was sentenced to 15 years for the shooting and was released on parole earlier this year.
"It was hard because all I think about is her kids," Williams said. "No matter what, my sister is not coming back for good behaviour."
However, she said she was working towards learning to forgive her killer, saying "the Bible talks about forgiveness... I would like to practice what I preach, and teach Olympia that as well... I'll be there."
