Los Angeles - Buoyed by victory at the Indonesian Masters 10 days ago, British world number three Lee Westwood will have to make do with a replacement caddie at this week's Wells Fargo Championship in Charlotte, North Carolina.

Westwood's usual bagman, Billy Foster, injured his knee in a charity soccer game on Monday and does not expect to be fit to return to duty until shortly before the June 14-17 US Open in San Francisco.

“He put his foot down wrong and has torn something in his knee,” Englishman Westwood told reporters on Wednesday while preparing for Thursday's opening round at Quail Hollow Club.

“He's out probably four weeks minimum, depending on the (MRI) scan that he's having on Friday when he gets back to England.

“He's set a goal for the PGA (Championship) at Wentworth, which is two-and-a-half weeks' time... but I think the Scandinavian Masters in Sweden the week before the US Open is probably more realistic.”

Westwood and Foster have worked together since the Irish Open three years ago and the Englishman will certainly miss his services, especially from tee to green, over the next fortnight.

“He knows my game really well,” Westwood said. “It'll be a loss for a few weeks, but accidents happen. He goes skiing twice a year and he's never done anything like that, and then he puts his foot down wrong on a football field having a kick around.

“But I've been out here (on tour) a long time. This is not my first rodeo. I think I'll be able to cope.”

Standing in for Foster for the next two weeks will be Casey Kerr, who has most recently worked for 1992 Masters champion Fred Couples.

“Case is a good caddie,” said Westwood, a 21-time winner on the European Tour. “He's proved that. He caddied for Fred and a lot of other good players. Fred was up there at the Masters (last month), so he's been in big arenas in contention.”

Westwood, who clinched his 36th tournament win worldwide with a successful title defence in Indonesia, could regain the world number one ranking with victory at Quail Hollow this week.

However, the 39-year-old from Worksop in England has more important objectives in mind.

“It's not really a priority,” Westwood said. “I'd obviously like to be world No. 1 again, but winning major championships is really my priority from now on.

“If I did that, then I think world No. 1 would come as a consequence,” he said, though added: “Winning this week is the priority for this week.”

Westwood has been excited by his early season form, having triumphed in Indonesia, finished second at the European Tour's Dubai Desert Classic and posted three top-four finishes in five starts on the 2012 PGA Tour.

“All my stats have been pretty good certainly early on in the year,” he said. “My short game stats are up, as well.

“Outside the PGA Tour, I've had a win and a second in Dubai. That's proof enough there. They're the best stats, results.” - Reuters