The tournament will be played for a fifth time on the Lake Course of the Olympic Club and the winning score is expected to be far higher than it was a year ago, when Rory McIlroy crushed the field with a record 72-hole total of 16-under 268.
That score was turned in at the Congressional Country Club, which became a relatively easy target due to the softness of the course. This year the players will face firm and fast conditions with thick rough awaiting any mishit shot.
McIlroy will be trying to become the first player since Curtis Strange in 1988 and 1989 to win the United States' oldest professional golf event two years in a row. Strange is the only player in the last 61 years to have recorded back-to-back victories at the Open.
A group of recent winners on the PGA Tour, however, could be in the picture. They include Masters champion Bubba Watson, Rickie Fowler, Matt Kuchar, Jason Dufner, Dustin Johnson and Tiger Woods, who will be looking for the 15th major title of his career and his first in four years.
Woods, Mickelson and Watson will be in the same threesome for the first and second days and they will begin their opening round at 7:33 a.m. PDT.
The United States Golf Association accepted 9,006 entries to this year's tournament and that number has been whittled down to 156 through a series of qualifying events.
There will be 23 major champions in the field and players from 20 countries will be competing. Shane Bertsch, whose only other U.S. Open appearance came when the event was last played at Olympic in 1998, will hit the opening ball at 7 a.m. PDT.