John McEnroe cannot be serious about Serena Williams.

What are the chances that former tennis great McEnroe made his outrageous statement about Serena to promote his new book? Probably 100 percent. That is typical McEnroe who, as the bad boy of tennis, would often start complaining to the head official about a call with the phrase, “You cannot be serious!”

Just as his new book, “But Seriously,” is coming off the press, Johnny Mac claims there are 699 men’s professional tennis players who could beat Williams, the greatest woman athlete of all time and perhaps the greatest athlete, period. To McEnroe I say, “You cannot be serious!”

McEnroe’s outburst while Serena is home getting ready to give birth also coincides with sneak previews of the new movie, “Battle of the Sexes,’ the story of senior Bobby Riggs playing Billie Jean King in a 1973 exhibition match at the Astrodome in Houston, watched by 40 million people on national television. In the movie, Oscar winners Steve Carell and Emma Stone play Riggs and King, and the trailers look great. Maybe McEnroe wants to get in on that action.

Perhaps Serena could not beat Federer or Nadal or Djokovich, but she could handle most of the other pro men with her powerful serve and volley game. The 35-year-old Williams has won 23 grand slam singles events and plans to return to the tour after her baby is born. McEnroe, who won eight grand slam titles, has been out of tennis for more than 20 years and this book is a long-awaited follow-up to his best seller of 2003.

Serena answered McEnroe with a couple of terse tweets, which is also remindful of how the retired Riggs, who won three Wimbledon championships among other titles, challenged King, at the time the top women’s player in the world. After King won, rumors began that Riggs actually took a dive in the match to pay back gamblers and loan sharks he owed thousands of dollars from his own betting addiction.

That match had a circus atmosphere but it turned the sports world’s attention to women’s tennis. Now maybe McEnroe’s remarks will do the same for a sport that Serena has owned for years. Perhaps the retired star, who still plays in a few senior and celebrity events, will even take on the women’s queen in Battle of the Sexes II. Seriously.

(AP Photo/Tim Ireland)