Limericke, Ireland -- The European Tour's Irish Open began Thursday at Limerick, Ireland, without Darren Clarke, last year's third-place finisher.

The native of Dungannon, Northern Ireland, withdrew this week because of a lingering right hamstring injury.

"To say I'm disappointed is putting it mildly," Clarke said. "I so wanted to compete for Ireland's national title so this is another blow on top of many recent frustrations. If I had played this week, I would have risked further damage and probably turned it into a long-term injury."

He suffered the injury playing with his sons two weeks ago and also pulled out of last week's Players' Championship in Ponte Vedra, Fla.

"I'm really down in the dumps after so many recent setbacks," he said.

Doctors told him after an MRI that, after intense treatment, the injury may recover enough to allow him to compete in next week's BMW PGA Championship in Surrey, England.

Copyright 2007 by United Press International.