IRVING, Tex. — Todd Demsey walked onto the first tee at T.P.C. Four Seasons Resort at Las Colinas on Thursday dressed in an off-the-rack golf shirt and khaki pants held up by a white cotton belt with a nondescript buckle. His clubs sat in a vintage lightweight leather golf bag with one divider, two pockets and no logos. On the brand-conscious PGA Tour, Demsey looked out of place, like a muni golfer who had crashed the Byron Nelson Classic.  The truth is, few pros have a better pedigree than Demsey, who won an N.C.A.A. championship, a Pacific-10 Conference title and the Pacific Coast Amateur while at Arizona State, where he was a four-time All-America selection. Demsey was pegged for stardom when he turned professional in 1995. A chronic back injury and two operations for a benign brain tumor have limited him to two tours on the PGA circuit.  “He has a lot of game,” said Phil Mickelson, a recent inductee into the World Golf Hall of Fame and a former teammate of Demsey’s at Arizona State. “He is a really, really good ball striker and has always had a lot of talent, been a tough competitor, and he and I have had great matches over the years. I have always expected and still expect to see him succeed.”  On the tour, the difference between success and failure can be harder to judge than where the fairway ends and the first cut of rough begins. Demsey’s health problems clipped his practice and preparation, which pruned his confidence, which curtailed his consistency.  David Duval, who lost the 1993 N.C.A.A. individual title to Demsey by one stroke, is ranked 676th in the world, down from No. 1 in 1999. “I’ve had my share of setbacks, so I know what it’s like,” he said. “It’s tough. I do admire the work ethic, the keeping at it, the belief in himself that he’s shown.”  For more than three years, Demsey has eked out a living on the margins of the Nationwide Tour and in lesser pro events that are a day’s drive from his Arizona base. With his 40th birthday looming at the end of this month and a wife and two children under the age 6 to support back home in Scottsdale, Demsey feels a sense of urgency that his unhurried stride does not betray. Having regained his health, he has turned his attention to reclaiming his spot among golf’s elite.  “I’m never too far off,” Demsey said. “It’s just a matter of letting myself play well. You just have to go play golf and not worry about everything else, and that’s what I’m trying to do.” He added: “I feel I have a lot of years left in me. Physically, I feel the best I’ve ever felt.”  He gambled that his game was ready this past week, shelling out $100 to enter Monday qualifying and a shot at one of four spots. Demsey beat out several dozen other golfers to secure his place in the field. Playing in the last group off No. 1, in a threesome that included Steven Bowditch and Charlie Beljan, he started inauspiciously, with an errant drive that led to a bogey.  After making another bogey, on the third hole, Demsey was approached by the volunteer who was carrying the walking scoreboard for his group. Demsey listened with growing interest as the man described his receiving a diagnosis of a malignant brain tumor a few years ago, his subsequent surgery and continuing recovery.  “I probably wasn’t in the mood to start chatting, but I’m glad he came up to me like that,” Demsey said. “Listening to him tell his story, it sort of settled me down.”  Demsey reeled off four consecutive birdies on the front and three on the back nine on his way to a three-under-par 67. After he signed his scorecard, he was walking toward the clubhouse when a fan approached him and said: “It was a pleasure watching you play today. I’ve heard bits and pieces of your story. It’s very inspiring.”  He hears that a lot, Demsey said. “I’d rather be known for doing good things on the golf course,” he said.  In Arizona, Demsey’s college coach, Randy Lein, had tracked his round on the Internet. Lein is never surprised when Demsey shoots a low score, he said, because Demsey’s swing has changed little since he set a course-record 11-under 61 at Desert Mountain Renegade, then rated by Golf World as the toughest course in the United States, as a redshirt freshman in college.  “He’s one of the only guys where I can say I could watch him hit balls and feel as though I was getting better because he has such a rhythmic swing,” Lein said by telephone.  Demsey can repeat his swing, but could he duplicate his low score in the second round? That was the question gnawing at Lein, who said: “It’s difficult because you’ve got to be ready to play when you do have these opportunities. You have to be able to seize the moment.”  On Friday, Demsey made seven bogeys on his way to a 77 and missed the cut by two strokes. Instead of a potentially big payday, Demsey was staring at a shortfall because of his travel and lodging expenses for the week.  Lein said, “I’ve had a lot of people ask me, ‘How does Todd afford to keep going out there?’ ”  When the question was conveyed to him, Demsey said: “I guess people don’t pay attention. I’ve been a pro for 17 years and I’ve made enough money to keep going.  “The last two years have been really bad, but I’m proud that I’ve been able to play the game for a living and support my family. Not many people can do that.”
After overcoming a back injury and brain surgery, Todd Demsey has struggled to regain his form and a spot on the PGA Tour.