Lee Westwood could face Ryder Cup heartbreak after pulling out of the WGC-Bridgestone Invitational in Ohio because of a calf injury (Europe – 8/15 to beat USA).

The world number three says the ruptured plantaris muscle in his right calf is giving cause for concern, and he cannot at the moment guarantee he will be fit for October’s clash with USA.

The 37-year-old suffered the injury at the end of June, and has been struggling since although he managed to play through the pain to finish second to Louis Oosthuizen (66/1 – to win the USPGA Championship) in the Open at St Andrews.

Overnight, he pulled out of the Bridgestone event and also announced he would not be competing at next week’s USPGA Championship.

“I will be out for as long as it takes to get right,” Westwood told reporters after a second round of 76 left him seven over par at Firestone.

“Hopefully it will be in time for the Ryder Cup.”

Westwood added: “It just seems to be getting worse. There’s no strength in it.

“I don’t have a deal of confidence in it, and then on the way down I’m finding it hard to hold my weight on it and then push off.”

Asked what he could do to get better, Westwood added: “Sit on my backside for six weeks like they keep telling me. It’s the only way to improve it.

“I’d like to be working out and I can’t put any weight on it in the gym, so my legs feel weak. That’s just it.”

Six weeks out would leave Westwood with around two weeks to get ready for the Ryder Cup at Celtic Manor, which starts on October 1.