LOUISVILLE Kentucky (Reuters) - American Jason Dufner aborted his PGA Championship title defence after 10 holes in Thursday's opening round at Valhalla Golf Club, withdrawing from the event because of a lingering neck injury.
Dufner has been severely hampered by two bulging disks in his neck since April and was eight over par for the day, having triple-bogeyed the par-five 10th, when he decided to pull out of the year's final major.
He shook hands with his playing partners, fellow American Keegan Bradley and South Korean Yang Yong-eun, who are both former PGA Championship winners, before leaving the course.
"I've been feeling pretty bad all week," Dufner told reporters. "I felt bad last week. I haven't made a birdie in 45 holes and I'm just not able to play golf right now.
"I don't need to be out here. I tried to do what I could to be able to compete some and give it a go, but it is just pointless."
Dufner, a three-times winner on the PGA Tour, had to limit severely his preparation for the tournament after having an epidural and being advised by doctors to take as much rest as possible.
"They like you to rest seven to 10 days after that," he said on the eve of the PGA Championship. "I haven't really been able to do that, so I'm trying to rest, keep my reps down. I feel sore. I get a little fatigued quicker than usual.
"It's an arthritic, degenerative issue that I'm probably going to be dealing with for a good bit. It's just something that's not going to change. I'm going to have to deal with it."
Dufner, who has been troubled by the injury since the Masters in April, said he would not be healthy until he was able to take a break from the game of six-to-eight weeks.
"Not sure when that's going to be, but I'll get through it," the 37-year-old said. "Obvious reasons for playing this week; defending (the title) is pretty important to me."
Dufner won his first major with a two-shot victory in last year's PGA Championship at Oak Hill.
His withdrawal on Thursday also puts his Ryder Cup spot in jeopardy with the United States set to take on holders Europe at Gleneagles in Scotland from Sept. 26-28.
The top nine players in the U.S. point standings after this week will automatically qualify for Tom Watson's team and Dufner was in eighth spot heading into the PGA Championship.
"I have a plan in place if I make the Ryder Cup team after this week; I have another plan in place if I don't make the Ryder Cup team," he said.
(Reporting by Mark Lamport-Stokes; Editing by Frank Pingue)