Andy Roddick, John Isner and 5 Other Americans Poised for Success in '12

At the ATP World Tour Finals a few weeks ago, the lone American representative was World No. 8 Mardy Fish. Andy Roddick, currently 14 in the standings, held that role at the event before, but for 2012 he's out to make sure Fish has some company from a compatriot. Other American men also stand to make gains on the top 10 next season, or could hit new highs in the rankings. Here's a look at some of them.

Andy Roddick

Roddick finished 2011 outside the top 10, the first time that happened since 2001. One of the game's veterans, Roddick finished the year solidly with quarterfinal appearances in his three of his last five tournaments, which included the U.S. Open. Fitness, his serve and his forehand can help him reach the lower tier of the top 10 in '12.

John Isner

The big-serving star had a career year in 2011, which saw him win two tiles and reach the quarterfinals of the U.S. Open. Maintaining a level of consistency that he's been working hard to build the past few seasons can help him reach lofty status.

James Blake

Even though he'll be 32 going into the '12 campaign, Blake has shown he's not done yet. In 2011, he won two titles on the Challenger circuit, as well as notched a win against Juan Martin del Potro. A return to the top 25 for the former world-four can't be easily discounted, as he's getting more match play than he had in 2010 due to injury.

Sam Querrey

A player who could almost do no wrong in 2010 was hit by the injury bug quite seriously in '11, missing a significant portion of the season. He's been forced to make his way back up the rankings through Challenger matches, and has risen to the occasion. The progress should continue in '12.

Wayne Odesnik

Though he may not be the most popular player on tour, by any means, there's no denying what he accomplished over the year. going from being unranked at the start to 129 at season's end. Progress interrupted by a drug scandal appears to be back on track.

Steve Johnson

A true up-and-comer, college star Johnson has seen his ranking fly upward while still dominating at the University of Southern California. The perennial All-American possesses a big enough game to make waves at the pro level.

Jack Sock

There's a lot expected of the 19-year-old, but that's what happens when you win a Grand Slam title as the Nebraskan did with fellow American Melanie Oudin at this year's U.S. Open.

Sock also won a round in singles at the tournament before falling to Roddick. He's a versatile, heavy-hitting young player already ranked in the top 400. 2012 could be the year that he advances even further up the rankings ladder.