At just 21 years old, the window may already be closing on American Sloane Stephens' opportunity to climb into the top echelon of women's tennis.
Two years after being the darling of the 2013 Australian Open, Stephens had her 2015 tournament cut short in the first round on Tuesday when she suffered a straight-sets defeat at the hands of two-time champion Victoria Azarenka.
The 6-3, 6-2 loss marks another blow for Stephens, who has failed to build on her early promise and is now struggling with inconsistent play.
In 2013, Stephens came into Melbourne ranked 25th in the world. She played the best tennis of her career over that fortnight—beating favorite Serena Williams 3-6, 7-5, 6-4 in the quarterfinal before falling to eventual champion Azarenka in the semifinal.
At the time, ESPN called Stephens "America's next big thing and the heir apparent to Williams." She showed promise for the following year, reaching at least the fourth round in six consecutive Grand Slams and climbing to the World No. 11 ranking by the end of 2013.
Even when Williams avenged her Australian Open loss with a straight-sets win over Stephens at the 2013 U.S. Open, she said of her opponent's game, "I don't think she has to work on anything. I think she is at the next level" (per Jane MacManus of ESPN.com).
At the time, Stephens' main tool was a power game that was believed to be on par with Serena's. But the youngster has failed to build on her potential and, in fact, has taken a step backwards. She has now stumbled in her past three Grand Slam appearances and is still waiting to reach her first final in any tournament.
As her frustrations have built, Stephens has developed a reputation for petulant behavior and giving up on games, as this Bleacher Report column from March 2014 explains.
Early exits at the 2014 Wimbledon and U.S. Open tournaments were followed by a season-ending wrist injury last September, with an accompanying drop to No. 34 in the world rankings.
As she rehabbed her injury and prepared to embark on her make-or-break 2015 season, Stephens re-hired her old coach Nick Saviano, per Stephanie Myles of OpenCourt. Saviano was a familiar face who had guided Canadian Eugenie Bouchard's spectacular breakout last year.
"I've known him since I was 10 years old," Stephens said after losing to Azarenka for the third consecutive year on Tuesday. "He basically taught me all of my technique, taught me everything I know, so definitely the trust is there, and I know he can help me a lot."
When she's on her game, Stephens' first serve is a powerful weapon. It failed her on Tuesday, when she won just 57 percent of her first-serve points compared to 81 percent for Azarenka.
Now a known entity after three years in the world top 100, Stephens' game has developed a predictable quality that allows her opponents to develop counterattacking strategies.
"Stephens, 21, again lacked the consistency and the variety required against Azarenka," suggested Christopher Clarey of the New York Times. "Although Stephens is just as powerful, she is not yet as clean a hitter of the ball."
The tennis world hoped that Stephens' new coach would help set her back on track towards becoming an elite player. A first-round loss, even to her nemesis Azarenka, certainly deflates those expectations and has left Stephens struggling to pick up the pieces.
The question now: Where does she go from here?
Stephens is determined to make the most of the season that lies ahead.
"I'm obviously disappointed that I lost, but if I dwell on this, the next 25 tournaments I'm going to play this year probably would suck, too," she said after the match, per Jim Caple of ESPN.com. "I'm going to try to keep my head up and work as hard as I can."
We're more than 20 years removed from the days when the top ranks of women's tennis were dominated by teenagers such as Steffi Graf, Monica Seles and Martina Hingis, but Stephens' window of opportunity won't stay open forever.
In the two years since Stephens reached No. 11, her spot as the tennis world's ingenue has been seized by 20-year-old Bouchard, who's now ranked seventh in the world.
Meanwhile, U.S. top 50 players Varvara Lepchenko, Madison Keys and Coco Vandeweghe all advanced comfortably through their first-round matches in Melbourne. They'd like nothing better than to go deep into the draw and continue chipping away at Stephens' spot as American tennis' heir apparent.
While fans and media are eager to see a changing of the guard, no American woman has yet offered up a serious challenge to the veteran Williams sisters, who remain the class of the field. Thirty-three-year-old Serena remains virtually unstoppable as the world No. 1 while 34-year-old Venus is still respectably ranked as the second-highest U.S. woman at No. 18.
It has been hoped that maturity would help smooth some of the rough edges out of Stephens' game, but when it was suggested after her loss to Azarenka that a lower profile and less attention might help relieve some of the pressure that appears to be stifling her, Stephens' prickliness surfaced once again.
"It's not going to change because I lose and you guys are still here," Jim Caple reported her as saying.
You guys are still tweeting, you guys are still talking about me. It never really changes. Once you do something good and you're kind of—not that I'm bad at tennis and I haven't been great, but I'm a good tennis player, so there's something to talk about there. I don't think it goes away. Once it's there, it's there.
As Stephens regroups and looks forward to lots more tennis in 2015, new coach Saviano will have his hands full as he tries to help his protege live up to her massive early potential.
Stephens will need to improve her mental commitment and add an element of surprise to her matches if she hopes to get back on to the winning track in 2015.