Phil Mickelson, with distractions off golf course, tries to take pressure off at Pinehurst

Phil Mickelson believes Pinehurst No. 2 is such a complete test for the U.S. Open that he'll have to be focused on every shot.

That could be quite a challenge for the five-time major champion.

On the golf course, Mickelson is trying to ignore the high expectations for him to finally win the U.S. Open and join five other greats who have won the career Grand Slam. There's also the emotional connection he has to Pinehurst No. 2 from his first runner-up finish in 1999, just one day before his daughter was born.

Off the golf course, he was linked two weeks ago to an insider trading investigation involving investor Carl Icahn and Las Vegas gambler Billy Walters.

Mickelson says he usually does his best when everyone least expects it.