Phil Mickelson tees off on the fifth hole during the second round of the U.S. Open golf tournament at Merion Golf Club, Friday, June 14, 2013, in Ardmore, Pa. (AP Photo/Julio Cortez)
Phil Mickelson reacts after his birdie putt on the ninth hole during the first round of the U.S. Open golf tournament at Merion Golf Club, Thursday, June 13, 2013, in Ardmore, Pa. (AP Photo/Charlie Riedel)
Phil Mickelson reacts to a missed birdie putt on the 17th hole during the first round of the U.S. Open golf tournament at Merion Golf Club, Thursday, June 13, 2013, in Ardmore, Pa. (AP Photo/Morry Gash)
Phil Mickelson chips to the second green during the third round of the Masters golf tournament Saturday, April 13, 2013, in Augusta, Ga. (AP Photo/David J. Phillip)
Phil Mickelson walks past a scoreboard while walking up the ninth hole during a practice round for the Masters golf tournament Tuesday, April 9, 2013, in Augusta, Ga. (AP Photo/Charlie Riedel)
Phil Mickelson celebrates after making a long birdie putt on the seventh hole during the final round of the Waste Management Phoenix Open golf tournament on Sunday, Feb. 3, 2013, in Scottsdale, Ariz. (AP Photo/Ross D. Franklin)
Phil Mickelson reacts to his birdie putt on the first green during the third round of the Waste Management Phoenix Open golf tournament, Saturday, Feb. 2, 2013, in Scottsdale, Ariz. (AP Photo/Matt York)
Phil Mickelson gives a thumbs-up to the crowd after making an eagle on the 15th hole during the second round of the Waste Management Phoenix Open golf tournament on Friday, Feb. 1, 2013, in Scottsdale, Ariz. (AP Photo/Ross D. Franklin)