Female tennis great Serena Williams has hit back at John McEnroe in a curious row over her hypothetical position in the men's game, asking him to "keep her out of statements that are not factually based" and instructing him to "respect her and her privacy" as she prepares to have a baby.

McEnroe recently made headlines when he acknowledged Williams as the greatest female tennis player of all time but claimed that she would "be like 700 in the world" if she played with the men.

"If she played the men's circuit she'd be like 700 in the world," McEnroe said. "That doesn't mean I don't think Serena is an incredible player.

"I do, but the reality of what would happen would be I think something that perhaps it'd be a little higher, perhaps it'd be a little lower."

The 58-year-old's comments sparked a lot of discussion and debate while some deemed them unnecessary as Williams eventually responded to McEnroe via Twitter.

"Dear John, I adore and respect you but please please keep me out of your statements that are not factually based," Williams wrote on Twitter. "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."

Dmitry Tursunov, currently ranked at 701 in the world, has come out in McEnroe's defence and agrees with his stance.

The 34-year-old, who has a career-high ranking of 20, claimed that the three-time Wimbledon winner was not "trying to talk women's tennis down" before adding that he would most likely defeat Williams.

"I would hope that I would win against Serena," the Russian told the BBC. "It would be a similar argument to: who would run faster, the fastest woman or the fastest man? Tennis is becoming more and more a physical sport, so it's going to be hard for a woman to beat the men.

"It's not black and white, there are lots of factors to take into account. Physically I might not be in the best shape of my life but as an overall package I'm much better than my ranking would suggest. She is pregnant, and I'm not."

Tursunov also added that McEnroe knew his stuff and agrees that Williams is an "incredible player."

"I've never heard John say anything absolutely stupid - he knows his stuff," Tursunov added. "What he said about her [Williams] being an incredible player is correct - explosive, powerful and she puts in a lot of work. But I would hope that I would win."