While most of the headlines surrounding the 2013 tennis season are focused on the world's elite, quite a few second-tier players are poised to make a major career leap.
On the men's side, it would come as a surprise if any non-Big Four member managed to break through and win a Grand Slam. That being said, plenty of success can be achieved without winning a Slam.
The women's game is still muddled at the top, although Serena Williams has proven on multiple occasions that she is the best player in the world when she wants to be.
The next wave of stars are out there gaining experience, but it's unclear which of them are destined for superstardom.
The making of a tennis star is complex, as the mental aspect of the game is just as important as the physical at this level. A competitor's mental fortitude cannot be judged by looking at winners and unforced errors, so it's often overlooked by the average tennis fan.
Here are ten tennis players to keep an eye on once the calendar flips to the new year:
Milos Raonic possesses one of the most imposing playing styles on the ATP tour, and he has been rewarded for it during his short career. At just 21 years of age, Raonic is already the highest ranked Canadian ever.
Although most of his success has come on hard courts, Raonic is dangerous on every surface due to his two biggest weapons. With a booming serve and penetrating forehand, Raonic has the firepower to upset any player on any given day.
The future is bright for Raonic because aggressive players tend to be more successful due to their higher ceilings. Although courts are slower than they used to be, dictating the tempo of the match is still key in determining the outcome.
This will be the year that Raonic makes his first deep run at a Grand Slam, as the young Canadian will reach the quarterfinals of either the Australian or U.S Open.
Christina McHale is the fourth highest ranked American woman behind only the Williams sisters and Varvara Lepchenko.
The New Jersey native has compiled three consecutive winning seasons and is poised to make 2013 the best of her career.
McHale finished the 2012 season ranked 33rd, which was the highest year end ranking of her young career. Her fluid game may be her biggest asset, as she moves well enough to change the tempo of a point at a moment's notice.
In 2012, McHale posted victories over Petra Kvitova and Caroline Wozniacki, proving that she can beat the best in the world. McHale also played competitive matches against Maria Sharapova and Marion Bartoli.
McHale is most comfortable on hard courts, so look out for her at the Australian Open if she receives a manageable draw.
Kei Nishikori is the highest ranked player on this list, as he finished the 2012 season ranked 19th. The Japanese baseliner is included because he is poised to break into the Top 10 at some point in 2013.
Nishikori notched a handful of impressive wins in 2012, triumphing over David Ferrer, Tomas Berdych and Jo-Wilfried Tsonga.
The best Grand Slam run of Nishikori's career came at last season's Australian Open when he reached the quarterfinals. His results tapered off after that, as Nishikori was unable to win three straight matches again until October.
While he struggled to gain momentum in the middle of the schedule last season, he now has a grand opportunity in the upcoming season.
If Nishikori can make another deep run in Australia—which won't be easy—then he will have plenty of opportunities to pick up points and make his ascent up the rankings.
Cracking the Top 10 is a lofty goal, but it's achievable for Nishikori if he plays his best tennis.
The void that many assume will be left in American women's tennis after the Williams sister retire might not actually materialize, as a handful of young Americans have a lot of promise.
Leading that charge is Sloane Stephens. At 19 years old, Stephens finished the 2012 season as the world's 38th ranked player.
The young American employs a big forehand and never appears to be rattled in tense moments, a trait that cannot be taught.
During her first full season on tour, Stephens gave a handful of elite players all that they could handle. That list of players includes Marion Bartoli, Agnieszka Radwanska, Samantha Stosur and Angelique Kerber.
Tracking Sloane's progress will be interesting in 2013, as players her age tend to either take a big step forward or a big step back.
I don't see her regressing thanks to her mental strength.
Jerzy Janowicz finished the 2012 season ranked 26th, which is remarkable considering that he only played 18 matches all year.
He acquired the majority of his ranking points at one event, as Janowicz reached the finals at the Masters 1000 event in Paris. Although he lost in the final to David Ferrer, Janowicz announced his legitimacy with victories over Andy Murray, Marin Cilic and Janko Tipsarevic.
Janowicz's loss to Ferrer was his final match of the season, so the tennis world has had to patiently wait for his encore performance.
This pick could be considered a bit of a reach because Tamira Paszek has never produced consistent results off of grass courts.
Paszek has a big serve and is comfortable at the net, which explains the doubles success that she has enjoyed. Both of those skills are also critical to grass court success, which is where Paszek is most comfortable.
At Wimbledon in 2012, Paszek progressed to the quarterfinals before succumbing to Victoria Azarenka in three hard-fought sets. The ranking points she received from that event have aided her ranking, as Paszek ended the season at 30th in the world.
If Paszek can find a way to translate her success on grass to the other surfaces, then she will be a threat to crack the Top 15 in 2013.
Grigor Dimitrov has drawn comparisons to the great Roger Federer for years now. While both players employ one-handed backhands and powerful forehands, Dimitrov has a long way to go before the comparisons will be justified.
For Dimitrov to begin an ascent up the rankings, he needs to improve his conditioning. His lack of physical fitness was made apparent during the 2012 French Open when Dimitrov was overcome by cramps during his second round match against Richard Gasquet.
At 21 years of age, Dimitrov is still a few years away from reaching his prime. That being said, these are the years in which Dimitrov should be gaining valuable experience in big matches.
The hype that once surrounded Dimitrov has dissipated, which is exactly why I think he will break through in 2013. Now that he is under less pressure, he will feel more comfortable on the court and play better as a result.
Sorana Cirstea's goal is the reach the Top 10, but in order to do so, she will have to find more success at the Grand Slams. In 2012, Cirstea only won six matches at the Slams, as her performances in the majors hurt her ranking more than they helped.
Cirstea is on this list due to her dangerous groundstrokes, although they are often too erratic. If she can become more consistent from behind the baseline, then Cirstea will become a more complete player.
Since the Romanian also plays a fair amount of doubles, she is comfortable at the net. That's something that Cirstea should use to her advantage, as the change of pace could help her on big points.
Bernard Tomic is a difficult player to predict due to his inconsistent results and the apathy he shows at times.
After making a run to the quarterfinals at Wimbledon in 2011, it appeared as if Tomic, who was 19 years old at the time, would become a tough out at every tournament. That wasn't the case, as he has only progressed past the second round at a major once since.
In order for Tomic to break through in 2013, he will need to remain in good legal standing, which is something he has struggled with.
Even though he has taken a step back, at just 20 years of age, Tomic still has plenty of time to develop as both a player and person. In sports, the mistakes that young athletes make are publicized for the entire world to learn about.
Tomic deserves another chance in the court of public opinion, and he will be embraced if he is successful.
If he can stay out of trouble and focused on tennis, positive results will follow in 2013.
Laura Robson is Great Britain's best hope on the women's side, as the 18-year-old phenom has the talent to blossom into a Top 10 player.
Andy Murray and Robson represented Great Britain in the Hopman Cup at the beginning of the 2010 season when Robson was just 15 years of age. The duo played very well together in mixed doubles and made a surprise run to the finals.
During the event, Murray said the following about Robson according to TheAustralian.com:
I have got to say thanks to Laura because she was awesome. In mixed, the guys are supposed to try and dominate the match and help out a little bit, but every time I tried I lost the point. I just let her do it all herself and she did great.
Robson has steadily improved since then and ended the 2012 season ranked 53rd in the world. She claimed a notable victory over Kim Clijsters at the 2012 U.S Open, sending Clijsters into retirement.
Robson's victory over Clijsters could be viewed as a passing of the torch. That isn't to say that Robson is a lock to be as successful as Clijsters, but she is certainly one of the game's premier young talents.
After having to qualify for the 2012 Australian and French Opens, Robson will be granted direct entries into future Grand Slams if she can maintain her ranking.
Based upon her current trajectory, I would not be surprised to see Robson finish the 2013 season inside the Top 25.