Mickelson diagnosed with psoriatic arthritis

HAVEN, Wis. -- Phil Mickelson's uneven play in the wake of his Masters win now comes with an explanation: The golfer said he has psoriatic arthitis, a condition that left him with intense pain in his joints.

Mickelson said he first came down with symptoms prior to the U.S. Open, and was so stiff at times he could barely walk. After struggling through most of the summer, including a missed cut at the Scottish Open and a T-48 at the British Open, Mickelson said doctors from Mayo Clinic have prescribed a weekly shot of Enbrel that has dramatically helped.

"I've been a little bit concerned because we would be on a trip in Hawaii right after the Open, and I wasn't able to move and it was a little bit concerning," Mickelson said. "But I've had some great doctors and things have been looking great and long term there shouldn't be any issues."

Mickelson did acknowledge that his lack of preparation as a result of his arthritis means he's not as sharp as he'd like to be headed into the PGA. But he says he's been able to practice and even work out at close to a normal level, and that he's hopeful his game will rebound for the end of the season.

The player said he didn't reveal his condition until now because he wasn't prepared to talk about it.

"I didn't want excuses. Second, I don't want to discuss something when I don't know what the outcome will be," Mickelson said. "I feel better about it and I'm a lot more at ease about it.

More shocking might have been Mickelson's revelation that, as a result of his condition, he's been a vegetarian for the past seven weeks, a tectonic shift for a player with a known affinity for fast food.

"As long as I believe that there's a possibility that it will help me overall, yeah, I'll continue to do that. If it will somehow keep this in remission or stop it from coming back, yeah, I'll be able to do it," he said. "But I haven't been put to the real test. The real test is driving by a Five Guys and not stopping."

As has been the case for most of the summer Mickelson has a chance to supplant Tiger Woods atop the world ranking. The five ways it could happen include: a win at the PGA Championship; a runner-up finish with Woods out of the top three; a third-place finish with Woods out of the top 11; a fourth-place finish with Woods outside the top 46; and a two-way tie for fourth with Woods missing the cut.

-- Sam Weinman