British Open champion Darren Clarke has withdrawn from next month's U.S. Open in San Francisco because of a groin injury.
The 43-year-old Clarke told United States Golf Association officials on Monday that the problem that had bothered him for several weeks is still troubling him.
Clarke hasn't made a cut this year. He says: "I've not been able to get through the ball properly and I don't want to take any chances."
Clarke says he wants to make sure he is 100 percent fit for the defense of his British Open title at Royal Lytham on July 19-22 and "has been advised not to play for a month."
The U.S. Open is at the Olympic Club from June 14-17.