Westwood a doubt for Ryder Cup after succumbing to calf injury

Englishman admits he now faces a race against time to be fit to tackle the Americans at Celtic Manor in eight weeks

Lee Westwood marched into the WGC-Bridgestone Invitational with the world No 1 ranking in his sights. Last night he limped out in the grim knowledge that he would not be competing in the final season of the major and perhaps not even the Ryder Cup.

The Englishman withdrew after a second-round 76 in Akron and revealed his worsening calf injury means he will not be teeing it up in next week's USPGA Championship at Whistling Straits. Westwood's mission now is to be fit in time for the Europe team who will take on America at Celtic Manor in eight weeks. But he confessed even that may be beyond him.

"I will be out for as long as it takes to get better," said Westwood. "I am just hoping that it will be in time for me to play in the Ryder Cup."

The 37-year-old had his ankle taped yesterday and, playing alongside Tiger Woods, struggled to a seven-over total. Asked afterwards what else he could do to relieve the discomfort, Westwood replied: "Sit on my backside for six weeks, like they keep telling me. It's the only way to improve it."

After consulting with his management team Westwood eventually heeded the advice and accepted he would have to return home to Worksop immediately to begin his recuperation work. "It just seems to be getting worse – there's no strength in it," he said. "I don't have confidence in it, and then on the way down I'm finding it hard to hold my weight on it and then push off."

Westwood has already sealed his Ryder Cup place, but six weeks on the sidelines would leave him with just a fortnight to get match-fit for the physically-demanding match on a hilly course which starts on 1 October. Colin Montgomerie will be desperate to have him in Newport as his absence would be a huge blow. A veteran of six Cups, he has Europe's second best scoring strike-rate. He is the continent's top-ranked player and is also the Tour's reigning No 1, having won his second Order of Merit last November. He would have gone into the USPGA as one of the favourites having finished in the top three in four of the last five majors. He came within one putt of making the 2008 US Open play-off at Torrey Pines and also the 2009 Open play-off at Turnberry. He tied for third in last year's USPGA Championship at Hazeltine.

Westwood suffered the ruptured plantaris muscle two weeks before the Open, but still managed to finish second at St Andrews three weeks ago. He has not played since – and is plainly not sure when he will play again. "I'd like to be able to play my best and work my hardest, which I can't do," he said. "I can't even hit balls, you know? It's evident that I'm rusty since the Open because I haven't been able to practice. It's just a vicious circle, really."

Eerily this was the same event in which Paul Casey was forced to pull out due to a rib injury that was to keep him out for three months. At the time the Englishman was the world No 3. Just like Westwood.