Here was Billie Jean King’s initial reaction when she saw Roger Federer’s tweets suggesting that the men’s and women’s professional tennis tours unify:

“I went, ‘This can happen! This can happen!’” she said by telephone. “The time’s right.”

And then what came to mind for King?

“I know not to get too excited, though,” cautioned the owner of a total of 39 Grand Slam titles, 12 in singles. “Unless you’re shaking hands at the net, it’s not done yet.”

With his thinking-out-loud via social media Wednesday, Federer sparked a conversation about bringing together the WTA, which oversees the women’s circuit, and the ATP, its counterpart for men, to boost the sport. While such a move, if it actually happens, would be arriving about a half-century late, this most certainly is a case of better late than never, no matter what someone like 24-year-old Australian player Nick Kyrgios thinks.

“It just brought back memories of how hard we’ve been trying all these years for that to happen,” King said. “In my day, the men, culturally, just could not wrap their heads around us ever making a dime.”

She ushered in women’s pro tennis with a group called the Original 9, which signed a contract for a symbolic $1 to start a tour in 1970. Then she got the WTA going in 1973, a year after the ATP was formed.

Her push about 50 years ago to put men and women under one umbrella was not well-received, King recalls. So does another member of the International Tennis Hall of Fame: Donald Dell, a former player, Davis Cup captain, agent and co-founder of the ATP.

“The men always felt that they were more dominant in the sport,” said Dell, who played mixed doubles at Wimbledon with King in the 1960s. “Now, equal prize money has come into the sport, and the women’s game has grown and grown and grown to where there’s parity.”

Remember, though: It took until the 2000s for equal pay at Grand Slam tournaments to become standard.

Nowadays, Dell said, “It would be much better for the sport if there was a really intelligent way to combine the ATP and WTA into one working group.”

It might be complicated to figure out how to make it happen – Dell asks: Start with a commissioner’s office led by two people, one from each tour? – but the benefits could be enormous, both in terms of finances and appeal to the public.

As Federer noted: “It’s too confusing for the fans when there are different ranking systems, different logos, different websites, different tournament categories.”

He wasn’t advocating for competition to be combined. He was pushing for the sport to be run as one sport. And that would put it in a unique position, with global appeal, because it features men and women. They already share a stage at the four Grand Slam tournaments and combined events such as at Indian Wells or the Miami Open. Leave the schedules mostly as-is – although King would love to see more team events – and hold onto some women-only or men-only tourneys.

“The sport has spent so much time over the years cannibalizing itself, with different people selling different things,” said Federer’s manager, Tony Godsick. “If the sport really wants to grow and get to the next level – in terms of media, in terms of sponsorship, in terms of popularity and fan engagement – you have to not sell against yourselves, but sell yourselves together.”

That is really the key here: Coming up with a way to organize things.

“It probably should have happened a long time ago, but maybe now is really the time,” Federer wrote, with an eye to the financial woes facing players, tournaments and the tours themselves as a result of the coronavirus pandemic that has shuttered tennis until at least mid-July. “These are tough times in every sport, and we can come out of this with 2 weakened bodies or 1 stronger body.”

It’s what King advocated all those years ago and others did more recently.

Current Pac-12 Commissioner Larry Scott, for example, pushed for a merger before leaving his job as WTA CEO in 2009.

The current head of the women’s tour, Steve Simon, and the leader of the men’s tour, Andrea Gaudenzi, have been cooperating to deal with the consequences of the COVID-19 outbreak, whether figuring out possible schedules for the resumption of play or drumming up funds to help lower-ranked players.

“Tennis has always led the way when it comes to putting men and women together on the biggest stages,” Gaudenzi said via email. “It’s one of our strengths, and sets us apart from many other sports.”

Maybe it’s time to set themselves further apart by working jointly.