Former world No. 1, John McEnroe said Serena Williams was undoubtedly the best female player, but would figure at No. 700 in the men`s circuit`, while on a tour to promote his book "But Seriously". Obviously displeased at this comparison, Williams responded via Twitter asking for some respect.

She wrote, "Dear John, I adore and respect you but please please keep me out of your statements that are not factually based." In another tweet, she asked for privacy as she was "trying to have a baby."

Williams, who has seven Wimbledon and Australian Open, six US Open and three French Open titles to her credit, is just one shy of beating Australian Margaret Court`s all-time Slam singles title record. She won this year`s Australian Open final while pregnant and will not be participating for the remainder of the season.