Tiger Woods reacts on a green during a practice round...

Tiger Woods reacts on a green during a practice round before the start of the 115th U.S. Open Championship at Chambers Bay on June 15, 2015 in University Place, Wash. Credit: Getty Images / Ross Kinnaird

Coming off his career-worst 85 on June 6 at the Memorial, the deterioration of Tiger Woods' golf game has become as much of an enigma to his fellow tour pros as it is to him. Monday, he was back at it, teeing off at 7 a.m. on the 10th hole at Chambers Bay in preparation for this week's U.S. Open.

In the past, Woods would have been a prohibitive favorite on the wide-open, links-style layout because of his length off the tee and ability around the greens. Now, it's anybody's guess how he will fare.

Jason Day, who played with Woods and Dustin Johnson Monday, said most of the mystery revolves around Woods' scattershot driver. "If he could get on the fairway, he'd probably be back to where he was," Day said. "His iron play is just ridiculous how good it is right now -- really special. The driver gets a little wide sometimes.

"Who knows what's going on with Tiger right now? We're friends, but I don't get into his personal life. When it comes to golf, you could have all the tools in the world, but if you really don't want to be there or if there's something that's off course that's playing on your mind, it's very difficult to win golf tournaments."

Day said Woods' 14 major championships creates enormous expectations, but it's tough to live up to that pressure. "We put him on such a pedestal," Day said. "Where is the old Tiger? When is he going to come back? We're waiting for him to come back and win those tournaments like it was nothing. Will we see it? I'm not sure.

"He dominated the game so long . . . You're climbing Mount Everest, and he's fallen off it a couple times and climbed back up there. Once you understand how hard it is to climb Mount Everest, it's hard to do it again."

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