It has been a year since the world got to know Sloane Stephens in Australia. First there was her upset win over Serena Williams; then there was her controversial loss to Victoria Azarenka. What will she do for an encore?

If her record at the majors in 2013 is any indication, Sloane will be in the mix again. She reached the round of 16 or better at all of the Slams last year, which was enough to send her ranking from No. 38 all the way up to No. 12. Along the way, the 20-year-old showed that she can raise her game on the big stages, and put herself in pole position to become America's next great player.

The trouble is, Sloane wasn’t always great. She didn’t reach another semifinal after departing Melbourne; by mid-year, she seemed to be fed up with the press, the tour, the attention, the grind—even, it seemed, tennis in general.

Ad-In: She can be passive, but Stephens remains the real deal. She’s fast, she’s strong, she has easy power, she can pop a big serve when needed, and most important of all, she can put the ball past her opponents from the baseline. After spending the off-season with Paul Annacone, she should be heading for the Top 10.

Ad-Out: When Sloane’s good, she’s good; when she’s not, she’s...not, and she knows it. Stephens, with a world of expectations surrounding her, gets down on herself when she doesn’t meet them. An early loss in Australia would send her ranking tumbling, and maybe her confidence, too.

As we approach the new year, we'll take a closer look at what's in store for the past year's top performers. To read more of our 2014 Season Previews, click here.