The physical demands of elite-level tennis these days suggest that it’s a young man’s game. Yet experience, wise career management, and maturity have never appeared to play a larger role, and the player who best personifies that theory is 35-year-old Tommy Haas. The lithe, 6'2" native of Germany raised eyebrows when he finished 2012 just outside the Top 20 (No. 21). In 2013 he blew minds as he won two titles and completed the year 47-21.

A former prodigy who was farmed out to the Nick Bollettieri Tennis Academy at an early age, Haas has long been on the short list for best player who’s never won a Grand Slam. He’s been ranked as high as No. 2 (over a decade ago, in May 2002) and he’s been a Grand Slam semifinalist four times. But his recent exploits have cloaked him in a different kind of celebrity.

The highlight of Haas’ year was an upset of Novak Djokovic in the fourth round at Miami, after which he topped Gilles Simon but fell to David Ferrer in the semis. It was his only win over a Top 10 player on the year.

Ad-In: If Haas can retain his remarkable enthusiasm for the game and follow as successful a fitness and training regimen as he has for the past two years, there’s no reason why he can’t push the envelope even further. Anyone who saw him play in 2013 would confirm that he’s still cavorting around the court like a 25-year-old.

Ad-Out: If Haas begins to play the way we’ve always thought of a 35-year-old does, he’ll have trouble staying in the Top 100, never mind the Top 20. But the bigger danger for Haas, given how easily he’s borne his age so far, is injury. Time missed probably helped increase his longevity, but a history of injury equates to a constant threat.

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.