This series will focus on several up-and-coming men who could begin to make a name for themselves on the ATP World Tour. The first player featured  is American Jack Sock.

Sock began to show flashes of potential greatness in 2011. Although he never broke into the top 300 that year, he was competitive against players much better than himself on the Futures tour, and he won a match in the main draw at the US Open. Sock also won the US Open mixed doubles title at the age of 18 while paired with Melanie Oudin. The pair has not competed in mixed doubles since then, surprisingly in view of their success.

Since 2011, however, Sock has flown under the radar. He made a splash with that US Open win over Marc Gicquel but has not quite reached the spotlight afterwards. But that does not mean that he has been unsuccessful or that he has not evolved.

Sock’s improvement over the past few years is obvious to anyone who watches him consistently. His power and accuracy off the baseline continue to increase, as does his lethal second serve. His game looks like what seems to be standard among Americans these days—based off a big serve and follow-up forehand. Sock does play with a bit more spin than most Americans do, but it could be that he will start to flatten out his groundstrokes more as he grows stronger.

That area is where Sock has the most room to grow. He plays a powerful game from the ground, but he does not have quite enough power yet. His serve is strong but not deadly. He does have one of the better second serves in the game, but that alone will not win him matches.

Sock did take meaningful steps forward in 2013. He broke into the top 100 this season for the first time when he reached the second round of the French Open. He also reached the third round in the main draw of a major (the US Open) for the first time. He failed to qualify for Wimbledon, though, which is disappointing considering his game.

Sock has slipped just outside the top 100 at the very end of the year, but he has no points to defend from now until Memphis in February. Standing at world No. 104 right now means that he will have to worry a little about being left off the entry list for the Australian Open, but he most likely will get into the main draw without going through qualifying.

2014 should be Sock’s first full season competing just as much (or more) on the ATP World Tour as the Challenger Tour. How he adjusts to the change and whether he can allow his game to develop as he competes more often in bigger tournaments will shape his 2014 season and, possibly, the future trajectory of the rest of his career.

Yeshayahu Ginsburg's series continues next week with another young star worth watching next year.