Juan Martin del Potro remains an elite player lurking for his opportunity to return to the discussion with the Big Four. He is arguably the next biggest threat to conquer a Grand Slam.
Don't forget, he has done it before. He upset the heavily-favored Roger Federer in the 2009 U.S. Open. Who says lightning cannot strike twice?
After the best win in his young career, he endured a year-long wrist injury in 2010 that took years to fully recover.
The Argentinean-- currently ranked No. 8, highest since his injury-- finally rekindled his old form. His wicked whiplash forehand has been clocked over 100 mph. His monstrous serve consistently reaches 135 mph and has topped out at 147 mph.
His past few months have been very successful.
He lost to Federer in the semis of the Olympics in an epic 19-17 third set, which lasted four hours and 26 minutes: the longest in the storied history of the event.
He followed this disappointing loss with a victory over Novak Djokovic to earn a bronze medal.
Weeks later, he advanced to the semis at Cincinnati before falling to Djokovic.
He sports a tremendous 45-12 record this season and has reached two major quarterfinals this year.
Yet, the U.S. Open is his best surface.
Expect del Potro to make a deep run in New York and have an outside chance for the title.
The new del Potro returning to his old ways incites fear into the field, especially in the established hierarchy of the Big Four.