When the shock of Serena Williams’s third-round loss at Wimbledon settled in Sunday, American tennis was left to confront some uneasy questions. Chief among them: Will Serena and her elder sister Venus—together or individually—dominate the women’s game as they did from July 2001 to July 2003, when they won seven of nine Grand Slam titles between them?If not, do the sisters run the risk of being remembered less for re-writing the sport’s history and more as a cautionary tale about relying too much on talent and too little on hard work?And how could their failure to reclaim their place atop the game affect the popularity of tennis in the United States, which has been on the decline for years, save for spikes when the Williams sisters take charge?At 23 and 25, Serena and Venus are sufficiently young and gifted to script whatever sort of future they want in tennis. But their showing so far at Wimbledon, which took its annual day of rest on the mid-point Sunday, has been far from promising. ‘I had it in my head those two could really dominate and change the course of tennis and rewrite tennis in a big way,’’ NBC commentator and former touring pro Mary Carillo said on the eve of the tournament. ‘‘It’s so much up to them and how much they feel committed to being great.’’Serena’s straight-sets defeat on Saturday by 85th-ranked Jill Craybas, who in nearly a decade as a pro had never advanced past the third round of a Grand Slam, was her earliest Wimbledon exit since 1998, when she made her tournament debut at age 16.And Venus, who plays Craybas later on Monday, hasn’t looked sharp. Saturday she was tested by 20th seeded Daniela Hantuchova of Slovakia. ‘‘Venus played terrible today, in my opinion,’’ said Richard Williams, the girls’ father. Said Serena: ‘‘I think maybe she’s feeling her way through.’’Since winning the Australian Open in January (her seventh Grand Slam title), Serena played only 11 matches before Wimbledon—and none of them on grass. She withdrew from events because of ailments and injury, including a gastrointestinal illness, sore right shoulder and left ankle sprain. She also bowed out of events by saying she didn’t want to compete if she didn’t feel she could win.Venus also arrived at Wimbledon without much match-toughening. Her only title this year, in Istanbul, came against a draw of relative unknowns. A 15-year-old bounced her from the French Open, in the third round.Still, top-ranked Lindsay Davenport argues it’s far too early to conclude they won’t get themselves back to the top. ‘‘They have the games, and they have to ability to do that,’’ said Davenport, 28. ’’(The problem) has been consistency and being able to play tournaments healthy. I think they have been plagued by quite a bit these last 18 months. Injuries, and the injuries led to some confidence problems.’’As the Williams sisters sort out their priorities, former touring pro Leslie Allen, who is also African-American, feels their impact on tennis will remain strong. ‘‘What they did is they brought a whole new audience to tennis,’’ Allen said. ‘‘People who didn’t traditionally look at tennis began to watch it. And they weren’t necessarily people of color. Their reach was so broad, so universal because they were the atypical tennis player.’’But there aren’t many American girls currently among the elite junior ranks. ‘‘There are no young (American) women coming up, and that’s a big concern,’’ Carillo said. ‘‘We’re seeing not just Russians, but Serbo-Croatians and Bulgarians, apart from (the traditionally strong) South Americans on the women’s side. . They’re going after it in a way that doesn’t seem to be happening in this country.’’(LA Times-Washington Post)