US Open Tennis 2012: Dark-Horse Contenders to Watch For on Men's Side

The US Open will be about dark-horse contenders on the men's side in 2012.

Sure, Roger Federer, Novak Djokovic and Andy Murray will dominate the headlines in New York City this summer, but the lower-ranked players will make just as much noise with their play on the court.

Whether it's Juan Martin del Potro breaking through for the second time in his career at the US Open, or a Serbian player who has taken a backseat to the Djoker shining bright, the dark horses will make their presence felt at Flushing Meadows this August and September.

Without further ado, here are the top dark-horse contenders to watch for on the men's side at the 2012 US Open.

Juan Martin del Potro

Juan Martin del Potro has hoisted the US Open title once before, just three years ago in 2009, when he took down Roger Federer in the final. Del Potro is still only 23 years old and coming off an Olympic bronze medal this summer at the 2012 London Games. 

The current world No. 8 is 15-4 all-time at the US Open, losing in the third round last year after missing the 2010 US Open. There is no denying that the year's final Grand Slam is del Potro's favorite based on his success rate there. 

The combination of del Potro's recent Olympic success, his history of success at the US Open and his youth make him the No. 1 dark-horse contender outside of the "Big Three" this summer.

Del Potro's one career Grand Slam is one more than Andy Murray can boast, which is the most powerful argument one can make for the Argentine. 

John Isner

The United States' best shot at bringing home the 2012 US Open title lay with John Isner. The 6'9" American made it all the way to the quarterfinals at Flushing Meadows last year and boasts an 11-5 career record at the Grand Slam tournament.

Isner will have plenty of crowd support all tournament long as the top-ranked American player on the men's side. He also has the experience of a 2011 quarterfinal appearance under his belt, which will make his venture into the later rounds that much easier.

After a disappointing first-round loss at Wimbledon last July, Isner is flying under the radar and will be playing with house money the further he goes at the 2012 US Open.

With that said, expect the tall dark horse to contend on the men's side this summer.

Janko Tipsarevic

The 28-year-old Serbian tennis star finally broke through at a Grand Slam tournament last summer, earning a quarterfinal berth at the 2011 US Open. So, why is that important? It's worth noting because Janko Tipsarevic hasn't been that far in a major tournament before or since.

Tipsarevic is ranked No. 9 in the world heading into the 2012 US Open and will be a threat to conquer Flushing Meadows based on the fact that he has plenty of experience against the world's best. Tipsarevic has beaten fellow Serbian Novak Djokovic twice and edged Andy Murray once in his career as well.

If Tipsarevic can dig deep and find the magic formula against tennis' top stars again in 2012, then he could find himself in contention for a rare Grand Slam championship.

Follow Bleacher Report Featured Columnist Patrick Clarke on Twitter for more reaction and analysis on the 2012 US Open this summer.