While most of tennis's elite will be skipping the Campbell's Hall of Fame Tennis Championships in Newport, Rhode Island this week in order to prepare for the Olympics, the road to victory will not be an easy one for the tournament's competitors due to the presence of one man: John Isner.
Isner, the top-ranked American in the world (No. 11) and the tournament's defending champion, is the best player in the tournament by a somewhat sizable margin. Only one other top-20 player will play in the tournament, and Isner only has one challenger who has won more titles.
Still, Isner's victory is far from a lock. He has played progressively worse in each of this year's three Grand Slam events, culminating in a first-round Wimbledon loss to Alejandro Falla.
He also hasn't won a title since last year's Winston-Salem Open, though he reached the finals at both Indian Wells and the US Men's Clay Court Championships this year. And though much of Isner's top competition at Newport are short on titles, they represent some of the brightest and most promising young talent in the sport.
Here is a look at the six opponents with the best chance to prevent John Isner from repeating at Newport.