"I don't feel very good about what happened, of course," he said. "It's very disappointing. But I've got to take some time, and give this aggravation a rest."

He'll decide next week whether to play in the U.S. Senior Open on June 26-29.

Irwin's back has been bothering him off and on for several weeks, and he's been treating it with ice and electronic stimulation. He felt fine early in the round, and didn't think it was going to be a problem.

But his back "seized up" after his tee shot on the par-4 12th. He did some stretches in hopes of loosening it up. But after hitting an errant second shot that sailed a couple of hundred yards left of the fairway, he called for medical attention.

He lay down on the back of a cart, pulling his knees up to his chest to stretch for several minutes before being taken to the course medical center.

"Nothing I could do," said Irwin, who was 1-over when he withdrew.

A member of the Hall of Fame, the 58-year-old Irwin won the 1974, 1979 and 1990 U.S. Opens. He has 30 victories on the PGA Tour and 37 as a senior, and his career earnings of almost $30 million are second only to Tiger Woods.

• Bad break for amateur: Having Tiger Woods as a playing partner at the U.S. Open didn't unnerve amateur Ricky Barnes.

Playing with a foreign driver did.

The U.S. Amateur champion snapped his regular driver on the practice range minutes before teeing off with Woods and Ernie Els yesterday. His caddie, older brother Andy, quickly found a replacement, but it was inches shorter than Barnes' normal club and impossible to control.

"It was a struggle to go over to the first tee knowing that you don't even have your driver to play on a U.S. Open course," Barnes said. "My brother gave me a driver on the (first) hole and said this is all we could find.

"I didn't find the fairway with the driver and I think I hit it six or seven times. That's not very good."

The rest of his game was, though.

The 22-year-old who just finished his senior season at Arizona matched Woods shot for shot for most of the round, missing a short putt and bogeying the final hole for a 1-over 71. Woods was even par.

• Shaky start for 16-year-old: It took a few holes for 16-year-old Tom Glissmeyer to control a bad case of nerves.

Once he did, his game fell in line, too.

The youngest entrant in the Open shot a 10-over 80. He got off to a tough start, bogeying five of the first six holes. But he rebounded with pars on three of the next four, and went on to have a solid round for a high schooler competing against the world's best.