From a physical standpoint, it was shoulder bursitis that ended Maria Sharapova's season in August, when she pulled out of the U.S. Open and never returned. Mentally, though, it felt as if Sharapova’s 2013 ended with the French Open final. Like Victoria Azarenka at the U.S. Open, Maria was never a factor after giving her best against Serena Williams—only to come up short again. She would win just one more match in 2013.

Where will that leave Sharapova in 2014? Her will to win has never wavered in the past, even after other injuries and defeats, and she usually comes out of the blocks fast in Australia, where she was the champion in 2008. But she’ll be starting the season with a new coach, Sven Groenfeld; the man who was with her during her latest resurgence, Thomas Högstedt, is now working with Caroline Wozniacki. Maria, who has been on tour since she was 15, will be 27 in April. At some point, the miles and the injuries will begin to take their toll.

Ad-In: There was a sense last summer, even before her shoulder injury, that Sharapova needed to get away—the losses to Serena had mounted, and her disastrous experiment with Jimmy Connors as coach had wasted most of her summer. Maybe, motivation-wise as well as healing-wise, a six-month break was just what the doctor ordered.

Ad-Out: Sharapova has been at it for more than a decade already, she’s had multiple shoulder injuries, she’ll be 27 this spring, and she hasn’t beaten Serena since 2005. Her unshakable drive has always been her best asset. At some point, it might shake, especially if she her relationship with Groenefeld doesn’t show immediate results.

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.