FILE - In this Jan. 28, 2017, file photo, Serena Williams holds up a finger and her trophy after defeating her sister, Venus, in the women's singles final at the Australian Open tennis championships in Melbourne, Australia. Serena Williams is briefly back at No. 1 in the WTA rankings, despite not having played a match since January, and with plans to take the rest of 2017 off because she is expecting a baby. Thanks to a calendar quirk, Williams moved up one spot from No. 2, swapping places with Angelique Kerber. (AP Photo/Aaron Favila, File) (The Associated Press)
Serena Williams responded to tennis great John McEnroe's claim that she couldn't beat most men on the professional tour, writing on Twitter Monday that the commentator should "keep me out of your statements that are not factually based."
McEnroe told National Public Radio over the weekend that Williams is the best women's tennis player in history -- "no question." But when asked whether she was the sport's best ever, regardless of gender, he made clear he didn't think so.
He said he thought Williams could beat some men, "but if she had to just play the circuit -- the men's circuit -- that would be an entirely different story." He said if she tried to be part of the men's tour, "she'd be like [ranked No.] 700 in the world."
June 18, 2016: John McEnroe, watches Milos Raconic play Bernard Tomic during their semifinal tennis match at the Queen's Championships London. (AP Photo/Tim Ireland, File)
Williams has won 23 women's Grand Slam singles titles — a record for the Open era, which dates back to 1968. She is taking a break from the tennis tour because she is pregnant and plans to return to competition in 2018.
McEnroe won seven men's Grand Slam singles titles, all between 1979 and 1984. He interview on NPR was part of a promotional tour for his new memoir, "But Seriously."
The Associated Press contributed to this report.
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