It's been 31 years since he won a grand slam title but 56-year-old John McEnroe believes he could beat women's world number one Serena Williams.
Appearing on the late night TV show the Jimmy Kimmel Show, the seven-time grand slam winner said he could defeat Williams, a winner of 21 grand slams.
"I believe that I could still take her," McEnroe said with a wide smile.
McEnroe said he has hit with Williams and said his daughter's probably think he would lose.
Williams is aiming to complete a grand slam sweep with victory at the upcoming US Open.
McEnroe, who retired in 1992 before a brief comeback 14 years later, said Donald Trump attempted to set up a match between McEnroe and Williams in 2000.
"Fifteen years ago Donald Trump ... made an offer which I felt like was not enough," McEnroe said.
"And I think he was humouring the two of us. And Serena, she's got a lot to lose by losing to an old fart like myself. And I've got a lot to lose because if I lose to - God forbid - a woman, then I'm not allowed in any men's locker room for the next 15 years or possibly the end of my life, so that's part of why it's intriguing."
In 1973, former professional player Bobby Riggs played women's top-ranked player Billie Jean King, in a made for television match, which King won in straight sets.