Phil Mickelson of the United States prepares to play off the 6th tee with his caddie Jim Mackay during the first round of the British Open Golf Championship at Muirfield, Scotland, Thursday July 18, 2013. (AP Photo/Scott Heppell)

Photo by: Scott Heppell

Phil Mickelson of the United States prepares to play off the 6th tee with his caddie Jim Mackay during the first round of the British Open Golf Championship at Muirfield, Scotland, Thursday July 18, 2013. (AP Photo/Scott Heppell)