Open Champion Darren Clarke has been forced to pull out of the US Open in San Francisco next month due to injury.

The Northern Irishman has been advised to rest a groin problem that first bothered him the week before last month's Masters and then resurfaced at last week's BMW PGA Championship.

Clarke has also withdrawn from next week's Nordea Masters in Sweden, meaning his next appearance is now expected to be the Irish Open at Royal Portrush starting on June 28.

"I am extremely disappointed as Open champion that I will not be able to play the US Open," said Clarke.

"But I have to make sure I am 100 per cent ready for Royal Lytham (his Open defence is on July 19-22) and I have been advised not to play for a month.

"I've not been able to get through the ball properly and I don't want to take any chances."

Golf 365