Dustin Brown hits a return against John Isner at the U.S. Men's Clay Court Championship tennis tournament on Wednesday, April 9, 2014, in Houston. (AP Photo/Houston Chronicle, Bob Levey) MANDATORY CREDIT
John Isner, of the United States, hits a return to Dustin Brown, of Germany, at the U.S. Men's Clay Court Championship tennis tournament, Wednesday, April 9, 2014, in Houston. (AP Photo/Houston Chronicle, Bob Levey) MANDATORY CREDIT
John Isner, of the United States, returns the ball to Nicolas Almagro, of Spain, during the Sony Open Tennis in Key Biscayne, Fla., Monday, March 24, 2014. (AP Photo/J Pat Carter)