Phil Mickelson

Phil Mickelson, of the U.S., prepares to tee off on the 15th hole during a practice round at Royal Lytham and St Annes in Lytham, northwest England, on July 17, 2012 ahead of the 2012 British Open Golf Championship, which began July 19.

Phil Mickelson tees off on the fifth hole — Getty Images/Stuart Franklin

Phil Mickelson, of the United States, tees off on the fifth hole during the second round of the 141st British Open Championship at Royal Lytham & St Annes Golf Club on July 20, 2012 in Lytham St Annes, England.

Phil Mickelson reacts after a shot on the ninth hole during the first round of the U.S. Open Championship golf tournament Thursday, June 14, 2012, at The Olympic Club in San Francisco.

Phil Mickelson watches his drive on the ninth hole as Tiger Woods gets ready to tee off during the first round of the U.S. Open Championship golf tournament Thursday, June 14, 2012, at The Olympic Club in San Francisco.

Phil Mickelson slams his club on the 15th fairway after a poor approach shot during the third round of the Masters golf tournament Saturday, April 7, 2012, in Augusta, Ga.

Phil Mickelson hits a tee shot during a practice round prior to the start of the 2012 Masters Tournament at Augusta National Golf Club on April 3, 2012 in Augusta, Ga.

Phil Mickelson gives a thumbs-up to cheering fans on the 10th hole during the third round of the Northern Trust Open golf tournament at Riviera Country Club in Los Angeles on Saturday, Feb. 18, 2012.

Phil Mickelson holds his trophy on the 18th green of the Pebble Beach Golf Links after winning the AT&T Pebble Beach National Pro-Am golf tournament in Pebble Beach, Calif., Sunday, Feb. 12, 2012. Mickelson won the tournament after shooting an 8-under-par 64 to finish at total 17-under-par.

Phil Mickelson, PGA, golf, tony romo — AP Photo/Eric Risberg

Phil MIckelson, right, shakes hands with Dallas Cowboys quarterback Tony Romo on the 18th green at Pebble Beach Golf Links during the final round of the AT&T Pebble Beach National Pro-Am golf tournament in Pebble Beach, Calif., Sunday, Feb. 12, 2012.

Phil Mickelson hits his tee shot on the ninth hole during the first round of the Deutsche Bank Championship golf tournament at TPC Boston, Friday, Sept. 2, 2011, in Norton, Mass.

Fans of Phil Mickelson, of the U.S., watch him play during the first day of the British Open Golf Championship at Royal St George's golf course Sandwich, England, Thursday, July 14, 2011.

Phil Mickelson signs autographs before the Par 3 competition ahead of the Masters golf tournament Wednesday, April 6, 2011, in Augusta, Ga.

2010 Masters

Phil Mickelson hits out of a bunker on the eighth hole during the final round of the Houston Open PGA Tour golf tournament on Sunday, April 3, 2011, in Humble, Texas. The defending Masters champion Augusta out-dueled Scott Verplank on Sunday to win the Houston Open by three shots, his first victory since earning his third green jacket last April.

In a photo taken with a fisheye lens, Lee Westwood, right, of England, watches as Phil Mickelson putts on the ninth green during the final round of the Masters golf tournament in Augusta, Ga., Sunday, April 11, 2010.

Phil Mickelson celebrates on the 18th green after winning the Masters golf tournament in Augusta, Ga., Sunday, April 11, 2010.

Phil Mickelson celebrates after winning the Masters golf tournament in Augusta, Ga., Sunday, April 11, 2010.

Former Master's champion Angel Cabrera, left, of Argentina helps Phil Mickelson put on his Masters jacket after his win at the 2010 Masters golf tournament in Augusta, Ga., Sunday, April 11, 2010.

Phil Mickelson reacts after making a birdie putt on the 17th hole during the first round of the U.S. Open Golf Championship at Bethpage State Park's Black Course in Farmingdale, N.Y., Friday, June 19, 2009.

Phil Mickelson blasts from a bunker on the 15th hole during the first round of the 90th PGA Championship golf tournament Thursday, Aug. 7, 2008, at Oakland Hills Country Club in Bloomfield Township, Mich.

Waves crash on the scenic seventh hole as Phil Mickelson and Brandt Snedeker walk the green — AP Photo/Marcio Jose Sanchez

Waves crash on the scenic seventh hole as Phil Mickelson, center, and Brandt Snedeker, right, walk the green during the third round of the AT&T Pebble Beach National Pro-Am golf tournament at the Pebble Beach Golf Links in Pebble Beach, Calif., Saturday, Feb. 9, 2008.

Phil Mickelson, of the United States, tees off on the first hole during the final round of The Barclays Scottish Open at Loch Lomond Golf Club on July 15, 2007 in Luss, Scotland.

Phil Mickelson hits out of the rough on the second hole during the third round of the U.S. Open golf tournament at Winged Foot Golf Club in Mamaroneck, N.Y. Saturday, June 17, 2006.