STANFORD, Calif. -- With the U.S. Open Series under way, it's the time of year when talk of America's Next Top Player gets a little louder. Especially when, as now, the position seems vacant.
Discussing the lack of prodigies lining up to take over from Serena and Venus Williams has become almost an annual rite of summer, but the "next" post isn't an easy one to fill. Just ask Melanie Oudin, who has openly flailed under the pressure of being anointed the great hope after reaching the fourth round of Wimbledon and the quarterfinals of the U.S. Open as a 17-year-old in 2009. From a career high of No. 31, she is down to No. 100 and has won consecutive matches only once this season. Last week, the now 19-year-old from Georgia lost in the first round of the Lexington challenger to No. 247 Chanel Simmonds. "She played better than me. There's not really much I can say," Oudin conceded afterward.
The only upside of the poor results might be lowered expectations. "I don't think everyone is looking at me to do all kinds of great things," she told reporters in a conference call this month. "That means I don't need to put pressure on myself. I just have to go out and play my game.
So with Oudin struggling to rediscover her formerly feisty self, who is there to carry the banner? The top-ranked American is Bethanie Mattek-Sands -- she's there by virtue of a nice midcareer rise and the injury-related slide of the Williams sisters, but, at 26, Mattek-Sands is hardly a new kid on the block.
But the supply isn't nearly as thin as it might appear at first glance. Don't look now, but two of the three youngest players in the top 100 are Americans -- 19-year-olds Christina McHale and Coco Vandeweghe (counting Oudin, it's three of the five youngest). The U.S. also has the youngest player in the top 150, 18-year-old Sloane Stevens, and there is already talk around even greener prospects, such as 16-year-old Madison Keys.
And because being the youngest isn't quite the surefire indicator it used to be, others worth noting include a couple of upwardly mobile 20-year-olds, Alison Riske and Irina Falconi, and 22-year-old Vania King and her surging doubles career. Success on the tour these days is less a matter of shooting up to the top than of improving one's way up. Take Mattek, who is at a career high of No. 30 after spending her teens and early 20s struggling just to get into the top 100. Or 21-year-old Wimbledon champ Petra Kvitova, who is said to have only begun playing full time at 16 and was hardly considered a serious contender until a couple of years ago.
Big-serving but erratic Vandeweghe, conscious she did not pick up a racket until the advanced age of 11, also is hoping to accelerate quickly. "A lot of it has to do with playing more consistently good tennis, you know, which I've been working on tremendously," the Californian said in an interview at the Bank of the West Classic this week. "I started a little late, so I'm a little behind how many balls these girls have hit -- for my hundreds of thousands, they've hit millions.
"[And] it's kind of my first year into the big leagues. I got to play Wimbledon and the French Open for the first time, going over to Europe for two months, so it's all new experiences and finding what works for me and finding myself on the pro tour."
Vandeweghe, who is working with the USTA's Tom Gullickson, is ranked No. 99 but will fall if she does not defend last year's quarterfinal result at San Diego next week. She would like to hit the top 50 this year, then aim higher. "When I started playing tennis, I set a goal for myself of being No. 1 in the world, and that's still my goal," Vandeweghe said. "But there's also intermediate goals in between, like making top 100, top 50, etc. So one step at a time."
McHale, a gritty counterpuncher, is the youngest player in the current top 100 at No. 67 and is looking to climb further by growing her game. "I think, for my size, I have to try to work the point first; I'm not going to outhit people from the baseline," said the 5-foot-7 New Jersey native, who trains regularly at the USTA center in Florida and considered a college career before deciding to go pro.
"I still have a lot to improve before I can get to the top level," McHale said, "all aspects of my game, continuing to look to try to come in more, or be a little more aggressive and getting a little bit stronger."
If Vandeweghe and McHale manage to make a splash, will they be able to avoid the Oudin syndrome of melting under the spotlight?
"I think it's fine," said McHale of the attention and focus on her as an American prospect in the summer months. "All I can do is, each time I'm out there on court, try my best and keep working hard.
"I try and think of these tournaments as any other tournament, just try and treat it as any other match at any other tournament."
"I definitely rely on my family a lot," said Vandeweghe, whose uncle, Kiki Vandeweghe, had a long NBA career and whose grandfather played for the New York Knicks. Her mother was an Olympic swimmer. "It's kind of like, 'All right, you made quarterfinals, but I've done this. You know, whatever.' They keep me grounded and understand that I'm my own person. And, you know, there's always things to improve on, so don't settle on being happy in the moment, you've got to keep your big-picture goal and keep working toward that."
However far they get, there's also a big picture to the future of American women's tennis. With an increasingly international mix at the top of the women's game -- there are 37 countries represented in this week's top 100 -- having a half-dozen names in that group isn't a bad effort. But the real demand is always for players at the very top, contending for majors, and the increasing age of today's breakout stars suggests the U.S. public will have to wait a little while to find out if it has a future Grand Slam champion working her way up the ranks. In the meantime, there's still Venus and Serena.
Kamakshi Tandon is a freelance tennis writer for ESPN.com.