Worries in a Williams-less world

KEY BISCAYNE, Fla. -- Inside the grandstand here at the Sony Ericsson Open, there is a festive (if slightly moist) air. David Ferrer and Somdev Devvarman are grinding -- one muscular rally consisted of 31 strokes -- in front of a full and fully engaged house.

Even the folks simmering in the 85-degree heat outside the hulking venue are enjoying some prime entertainment; world No. 1 Rafael Nadal is practicing and the crowds ringing Court E are shrieking with every good shot. There, over Rafa's right shoulder, a huge poster looms on the side of the grandstand:

Kim Clijsters, at 20 feet tall, slightly larger than life, is pictured alongside Roger Federer and Venus Williams, along with the cheery suggestion to "Enjoy the game." Venus is wearing a racy red dress and a cryptic, Mona Lisa smile.

While Clijsters and Federer -- both former champions -- are just beginning to work their way through the loaded draws, Venus is missing in action. Oh, she was here a week ago, meeting some media obligations, and lives just up the coast in a sprawling $2 million estate in West Palm Beach. But, citing an abdominal injury that knocked her out of the Australian Open, she withdrew before they could change that grandstand poster. With sister Serena beset with health issues including a very serious brush with several blood clots, this is only the second time since 1996 that neither of them has played in the tournament.

"It would be great to see them in the draw," Maria Sharapova said on Saturday, sounding sincere. "They're great champions. They've had a lot of success at this tournament. Yeah, I think the tour misses them, and I think it's great for our sport to have them back as soon as possible."

Venus, 30, won three Miami titles in four years from 1998 to 2001. Serena, 29, was a five-time champion between 2002 and 2008. Lately, it's been trending the other way. Serena lost in the 2009 final to Victoria Azarenka and Venus fell a year ago to Clijsters.

In the nine months since Wimbledon -- which Serena won -- the sisters have played a combined total of nine matches. They all belong to Venus, who reached the semifinals at the U.S. Open, before losing to Clijsters, and the third round of the Australian Open. Serena, who has not played since Wimbledon after cutting her foot in a Munich restaurant and undergoing corrective surgery, recently suffered a pulmonary embolism. She recently told a "Today Show" audience that the incident made her feel like she couldn't breathe.

It would be an overstatement to say that the WTA finds itself in a similar position as it contemplates a Williams-less world, but certainly their star power will be missed. Serena has said she'd like to return sometime this summer but, given the gravity of her condition, no one knows if that is realistic.

For context, consider that Serena and Venus have combined for 20 Grand Slam singles titles; the rest of the active players, including Sharapova's three, have a total of 11 majors. That's a yawning void.

"For fans, I'm sure," said Bethanie Mattek-Sands last week after she was ushered from the tournament by No. 1-ranked Caroline Wozniacki in the second round. "For the players, it's who you play. If they're not in your half of the draw, you don't worry about it. I guess maybe for the two that would play both of them it would make a difference."

Just maybe. Mattek-Sands is relevant in the discussion of the Williamses since she is, after No. 9 Venus and No. 12 Serena, the next-highest-ranked American woman, at No. 43. Mattek-Sands, 26, is 9-8 for the year, lost in the first round of the Australian Open and the second round at Indian Wells. There are three U.S. teenagers in the top 100 -- 19-year-old Melanie Oudin (No. 75), 19-year-old Coco Vandeweghe (No. 90) and 18-year-old Christina McHale (No. 98) -- but it might be a stretch to call them future top-10 players.

None of these players reached the round of 32 here, and McHale was the only one to get that far at Indian Wells -- a poor showing by any measure. The U.S. men, on the other hand, placed five in the final 32 -- not including No. 8 seed Andy Roddick, who was afflicted by a virus and several other issues when he was beaten Saturday by Pablo Cuevas. The ATP World Tour is projecting he'll fall to No. 15 in next week's rankings, his lowest since 2002.

The Sony Ericsson itself is in robust health, drawing huge, swirling crowds and throwing out some terrific matches, even a week before the men's final. On Sunday, No. 4 seed Robin Soderling tangled with 2009 U.S. Open champion Juan Martin del Potro in a third-round match. On Monday, No. 4 seed Samantha Stosur encounters Sharapova. This has dampened the effect of losing Roddick, Andy Murray, Fernando Verdasco, Milos Raonic, Na Li and Shahar Peer in the early going.

Venus may not be playing here, but she's had a presence. She attended the WTA players' party last week, dazzling the red carpet cameras with a bejeweled dress and all kinds of bling. But based on early returns this season, the future of women's tennis isn't quite so bright and shiny.

Greg Garber is a senior writer for ESPN.com.