PGA tour staple Phil Mickelson announced Tuesday that a recently-diagnosed case of arthritis left him nearly unable to walk just before the 2010 U.S. Open began.

The Associated Press reports:

Mickelson revealed Tuesday he has psoriatic arthritis, a condition he said causes the immune system to attack the body's joints and tendons. Weekly shots of Enbrel, which lowers his immune system, have brought the disease under control.

"I'm surprised at how quickly it's gone away, and how quickly it's been able to be managed and controlled," he said. "I feel 100 percent, like I say. But when I'm laying there on the couch and I can't move, you know, yeah, I had some concerns. But I feel a lot better now."

Along with the Enbrel, Mickelson—known as being a cheese burger connoisseur—has given up his beloved burgers to become a vegetarian to help treat the disease. It was a tough decision for him, but his dietary changes may help ease the symptoms of arthritis.

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

Red meat is one of many foods people with psoriasis and arthritis are told to avoid because it is known to increase inflammation. View Healthline's 8 Diet Tips to Treat Inflammation to learn more about how dietary changes can help treat swelling and inflammation.

As Mickelson told reporters, psoriatic arthritis is a type of arthritis where the immune system attacks the body. It is linked to the autoimmune disorder psoriasis. Along with a arthritis, psoriasis is characterized by red, flaky patches of skin.

View photos of psoriasis and learn about home treatments for the skin condition.

Read the rest of the Associate Press coverage of Mickelson's announcement.