Top 15 teenagers to watch out for on the WTA, ATP tours in 2015

With Madison Keys turning 20-years-old earlier this month, take a look at the current crop of teenagers on the ATP and WTA Tours for the 2015 season.

With Madison Keys turning 20-years-old earlier this month, it's time to take a look at the current crop of youngsters on the ATP and WTA Tours. From the top teens of Nick Kyrgios and Belinda Bencic to the more under-the-radar youth toiling away in the lower echelons of the tours, here are the names to know for the 2015 season. 

Top of the class

Nick Kyrgios 
Age: 19
Country: Australia
Current ranking: No. 37

Despite his limited play on the ATP Tour, Kyrgios is the face of the next generation of ATP talent. While others may have shown more consistency and resilience, Kyrgios has done something none of the other teens have: impacted the Slams. After backing up his breakthrough run to the Wimbledon semifinals last year by advancing to the quarterfinals of the Australian Open in January, Kyrgios became the first teenager since Roger Federer to make multiple Slam quarterfinals. He's a born entertainer with charisma and an explosive style that gets the crowd out of their seats. He plays his best tennis when all eyes are on him and you knew you were watching something special when he had the audacity to hit this between-the-legs winner against then No. 1 Rafael Nadal at Wimbledon, en route to the biggest win of his career:

[youtube=https://www.youtube.com/watch?v=7DJgHwseiDI]

Kyrgios has won Challenger events on every surface and when his big serve is clicking he's incredibly tough to break. But questions remain about both his physical resiliency and work ethic. He's played just three ATP Tour tournaments since Wimbledon, compiling a meager 1-3 record. Despite his ranking being high enough to earn direct entry into nearly any tournament, he shut his season down early in September 2014. In the last year he's struggled with a myriad of ailments and began this season nursing a back injury. This week's tournament in Indian Wells will be his first since Melbourne.

​Belinda Bencic

​Age: 18
Country: Switzerland
Current ranking: No. 37

When you catch Melanie Molitor's (Martina Hingis' mother) eye as a junior talent, the "tennis prodigy" label will follow you wherever you go. For the most part, Bencic has done well to manage the expectations that come from both being coached by Molitor early in her career and playing under the same flag as Roger Federer. Her rise over the last two years has been steady and workmanlike, culminating in her first Slam quarterfinal at the U.S. Open last fall. She was the youngest player to make the U.S. Open quarterfinals since—wait for it—Martina Hingis in 1997. 

Bencic's 2015 season has started with a whimper. She's won just one match in five tournaments, but the occasional dips in form shouldn't cause alarm. Her game is solid on both wings and a few growing pains are expected as she gets comfortable in her new position as a Top 40 player.

​Borna Coric

​Age: 18
Country: Croatia
Current ranking: No. 60

If not for Kyrgios' big splash at the majors, Coric would be the ATP hot property. Ranked outside the Top 300 to start last season, Coric was awarded the ATP Star of Tomorrow as the youngest player ranked in the Top 100. In his last seven ATP tournaments, he's beaten two of the ATP's Big Four in Nadal and Andy Murray and made two ATP semifinals, in Basel and Dubai. Pundits like to compare his all-court game to Novak Djokovic, and Coric isn't shy about embracing the compliment. "When I'm at my best I am more like Djokovic game-wise, when I'm not, I'm more like Murray," he told the Times of India. If that's your worst, that's not too shabby.

The next big things

Thanasi Kokkinakis

​Age: 18
Country: Australia
Current ranking: No. 124

In the shadow of his good friend Kyrgios, Kokkinakis has come into his own this year as he works his way through his first prolonged stint on the ATP Tour. While Kyrgios has the flashy game and charisma, Kokkinakis is the one who looks like he could be the more reliable and solid player. Seeing his friend succeed seems to have given him the confidence that he's ready to make 2015 his breakthrough year. In his first ATP match of the season he earned his first Top 25 win over Julienn Benneteau in Brisbane, and he followed it up with his first Top 15 victory, a win over Ernests Gulbis 8-6 in the fifth in the first round of the Australian Open a few weeks later. Since then he's successfully qualified at three consecutive tournaments in North America. He also secured a key win for Australia over Lukas Rosol at Davis Cup last weekend, coming back from two-sets to love down to win in five. It's just a matter of time until he cracks the Top 100. 

​Donna Vekic

​Age: 18
Country: Croatia
Current ranking: No. 84

By virtue of being coached by Tim Henman's former coach David Felgate during her early WTA days, Vekic has been a part of the hype machine for years. At 17 she reached her career-high at No. 62 in 2013. After winning her first WTA title last year in Kuala Lumpur she became the first woman under 18 to win a WTA title since 2006. With Madison Keys graduating to her 20s, Vekic is now the only teenager with an ATP or WTA title to his or her name.

But since splitting with Felgate last August, Vekic's results have been dismal. She has not won a WTA main draw match since September and is now in serious jeopardy of falling out of the Top 100. For a player that has never cracked the Top 50, that backsliding is cause for concern.

​Works in progress

Taylor Townsend

Age: 18
Country: USA
Current ranking: No. 96

Watch Townsend play for 30 minutes and you can see why she has the potential to change the women's game—and also why she has a lot of work to do to get there. The former junior No. 1 is already a world-class talent at the net and possesses good power off the ground. At a time when the women's tour has been dominated by pure baseliners, Townsend offers a different mix of variety and shots and she's deceptively quick around the court. But spells of inconsistency plague her game, due to poor footwork around the ball and a serve in need of an overhaul. Despite all those weaknesses, she cracked the Top 100 for the first time this year and has already taken Caroline Wozniacki to a tiebreak set twice.

Highlights from her big win over Alize Cornet at the French Open last year:

[youtube:https://www.youtube.com/watch?v=EkWfxw4Z9hc]

Ana Konjuh

Age: 17
Country: Croatia
Current ranking: No. 99

Just watch Konjuh's serve and it's hard to quiet those whispers that she will surely win a Slam one day. A former No. 1 junior, she and Bencic dominated the 2013 junior season, as Konjuh scored the two hard-court titles at the Australian Open and U.S. Open. Given her live arm, it's worrisome that she's already had to undergo surgery for her elbow in early 2014, but she rebounded to make the third round of Wimbledon and her first WTA semifinal at the Istanbul Cup. 

Alexander Zverev

Age: 17
Country: Germany
Current ranking: No. 136

"Sascha" (as he's called) comes from a strong line of tennis talent. His father was a former ATP pro and now serves as his coach and his brother Mischa currently plays on the tour. A former junior No. 1 and the 2014 Australian Open junior champion, Zverev made his first ATP breakthrough last season when, ranked No. 235 he came out of nowhere to make the Hamburg semifinals.

[youtube=https://www.youtube.com/watch?v=Lxy7XsDydkw]

Under the radar

Hyeon Chung

Age: 18
Country: South Korea
Current ranking: No. 122

Chung has yet to secure a Top 100 win—in fact, few of the ATP teens on this Under the Radar list have—but he's getting it done on the Challenger Tour. He's made the semifinals or better at the three he's played this season and won the tournament in Burnie. 

Yoshihito Nishioka

Age: 19
Country: Japan
Current ranking: No. 147

The Japanese are very excited about Nishioka's prospects. Like Nishikori, he doesn't cut a towering figure but his speed and work ethic have separated him from the pack of Japanese prospects. 

​Jared Donaldson

Age: 18
Country: USA
Current ranking: No. 174

Donaldson officially threw his hat into the ring in the quest to find the next American talent when he won his first Challenger title in Maui in February. 

Elias Ymer

Age: 18
Country: Sweden
Current ranking: No. 190

Remember when Sweden was a tennis powerhouse? In five to ten years, maybe they will be again. Ymer is the highest-ranked man out of Sweden—yes, at No. 190—and he's already earning some buzz with two Top 100 wins already this year over Jurgen Melzer and Igor Sijsling​. Ymer, who trains at Magnus Norman's Good to Great academy, will make his way onto a bigger stage once he gets his ranking up.

[youtube=https://www.youtube.com/watch?v=OrRj-Ovn1Ds]

Katerina Siniakova

Age: 18
Country: Czech Republic
Current ranking: No. 78

Another one in the long line of talent from the Czech Republic, Siniakova made her first WTA semifinal last fall in Moscow and earned her first win at a Slam this year at the Australian Open, where she beat Elena Vesnina. 

The waiting game

CiCi Bellis

​Age: 15
Country: USA
Current ranking: No. 215

If you beat a reigning Slam finalist in your Grand Slam debut at the U.S. Open at 15-years-old, you're going to get some people talking. Bellis earned that U.S. Open spot by becoming the youngest winner of the Girls' 18s National Championship since Lindsay Davenport. She went on to finish the season as the junior No. 1 and she's continued to compete well, winning her third ITF title this year. All in all, that's a noteworthy resume for a player few could have picked out of lineup just a year ago. 

Naomi Osaka

Age: 17
Country: USA
Current ranking: No. 236

Osaka wowed us all when she beat Sam Stosur in the first round of Stanford last year behind a startlingly powerful arsenal. She hasn't done much to back that up since—and she has yet to win an ITF title—but the potential is there. 

[youtube=http://youtu.be/H-yPb1a3i9U]