(CNN) -- Even for able-bodied golfers, the U.S. Open is a stern test of stamina. And this week's venue, the Olympic Club's hilly, tree-lined Lake course, is as demanding as it gets.
Casey Martin cannot walk for 18 holes, but nonetheless he will tee off in San Francisco on Thursday 14 years after he made his only other appearance at a major tournament, also at Olympic.
Back then he was at the center of controversy as he sought special dispensation to use a golf cart due to a birth defect which affects the circulation in his right leg, causing him severe discomfort.
"It's not great at times. I'm able to do it, but I'm in pain when I play so I'm grateful I have a ride to my shots," the 40-year-old told CNN.
"I deal with pain but it's bearable. It helps me sometimes to concentrate -- I realize there's only one thing I can do and I try to block out my leg."
Martin eventually won the right to use a cart, appealing to the Supreme Court after the PGA Tour fought hard to prevent what it considered a dangerous precedent contravening its rules. Legendary names such as Jack Nicklaus and Arnold Palmer were called in to testify against him.
In the end, it proved to be a storm in a teacup. Martin tied for 23rd at the 1998 U.S. Open but the Oregon-born golfer played only one full year on the PGA Tour -- in 2000 -- and finally quit the professional circuit after another season struggling on the second-tier Nationwide Tour in 2006.
Since then he has been coaching the University of Oregon's golf team, but he decided to have a go at last week's U.S. Open regional qualifying event despite limited preparation.
"It just came together. I haven't been playing much golf. I've been around it with my team, I coach them, and I practice a little bit but I don't play a lot of golf," he said.
"Leading up to that qualifier I was at the national championship with my guys, so I hit about 20 minutes worth of golf balls that week. It was kind of a random occurrence me getting in, but I'm glad I went through the qualifier and grateful I got hot at the right time and I get an experience like this as a reward."
While his early years trying to establish a place on the circuit were difficult, Martin is now hoping to cherish his return to the spotlight.
"My life changed on Monday night when I qualified -- phone calls and demands, and a lot of well wishers. Which meant a lot, it's been a really neat experience for me," he said.
"I haven't had much time for myself so I'm anxious to get inside the ropes and just go play. Realistically I don't know what to expect. It's so hard to quantify because I don't play a lot of golf and I certainly haven't competed in so long.
"So what does that mean when you go to a stage like this, where there's millions of people watching on TV and the golf course is so hard? I don't know. I don't even know what my golf should be, but I am going to give it great effort, enjoy every bit of it, add 'em up and see what that means."
Martin has already had a taste of what's to come after Tuesday's practice round with his former Stanford college teammate, Tiger Woods. They played together at the 1998 U.S. Open, when Woods -- who had already won the Masters by that stage -- tied for 18th.
"Man, it's great to see him. And just so happy in life. It's good to see him in a really good place" said Woods, who is seeking to win his 15th major title but his first since the 2008 U.S. Open at Torrey Pines.
"Unless you really know him, I don't think people have an appreciation of how much pain he's in. Just the everyday pain he lives with. He doesn't show it, doesn't talk about it, doesn't complain, he just lives with it.
"And you just look at him and he's always so happy. It's very easy to go the other way and be very bitter, because of how uncomfortable he is on a daily basis. But I think that's what makes him special. That's what makes him so different than everyone else -- he has such a strong will and such a strong spirit."