She told McEnroe to leave her out of statements that aren't "factually based"
Serena Williams has told John McEnroe to leave her out of statements that aren't "factually based".
McEnroe believes that the one of the greatest ever players in the history of tennis would only be ranked around 700 in the world if she was on the men's tour.
"If she played the men's circuit she'd be, like, 700 in the world," said McEnroe in an interview with NPR Radio.
"That doesn't mean I don't think Serena is an incredible player, and I suppose anything's possible; maybe at some point a women's tennis player can be better than anybody.
"I just haven't seen that in any other sport, and I haven't seen it in tennis. If she had to just play the men's circuit, it would be an entirely different story."
Williams is taking time out of the game as she's expecting her first child and tweeted that she "adores and respects" McEnroe - but asked for privacy and respect.
"Dear John, I adore and respect you but please please keep me out of your statements that are not factually based," she tweeted.
"I've never played anyone ranked 'there' nor do I have time. Respect me and my privacy as I'm trying to have a baby. Good day, sir."
Earlier this year, Williams won the Australian Open - her 23rd career Grand Slam - and revealed shortly after that she was pregnant at the time.