The Calgary golfer started feeling discomfort early in his second round and pulled out after nine holes. He was 4-over on the day and 5-over for the tournament, well back of the projected cut.

Ames hasn't felt comfortable with his swing for a couple months and has had trouble getting together with swing coach Dennis Sheehy to correct the problem. He thinks that might have contributed to the injury.

``As the day went on, it got worse and worse and worse,'' said Ames. ``At this stage right now, I decided to withdraw because it's just getting harder and harder for me to swing the club.

``I guess it's all the poor swinging for the last couple months. It's aggravated it even more.''

Ames, who won The Players Championship earlier this year, left the course almost immediately to receive treatment from Dr. Craig Davis.

The pain is centralized in an area near his mid-back _ a ``funny'' spot, according to Ames.

He got up-and-down from just short of the 18th green on his final hole before walking off. The pain had reached a point where he felt there was little other choice.

``I wanted to continue going but it was wise to withdraw,'' said Ames. ``It could have gotten worse.''

Ames is currently 14th on the money list with just less than US$2.4 million in earnings.

He finished 18th at the WGC-Bridgestone Invitational two weeks ago and is next scheduled to play at the WGC-American Express Championship near London two weeks from now. There is no cut at either of those big-money events.

His plan is to continue to get treatment so that he can straighten out his swing problems. Ames says it hurts just to hit the golf ball right now.

``If you're in the wrong position through impact or even in your backswing, something's going to compensate and eventually something's going to give,'' he said. ``Hence the reason why that particular part of the body has given way.

``I feel it the most on the follow-through. That's where I feel the worst _ at impact.''