Paul Casey dislocates shoulder while snowboarding
Paul Casey faces two months on the sidelines after dislocating his right shoulder snowboarding in Colorado.
He will be unable to defend his Volvo Golf Champions title in South Africa starting on 19 January and his hopes of a Ryder Cup return are in jeopardy.
"I am very frustrated as I was really looking forward to getting off to a fast start in 2012," said Casey.
The world number 20 looks set to miss the Abu Dhabi Championship where he was chasing a third victory in six years.
BBC golf correspondent Iain Carter
“This is a big setback for Casey, particularly in a Ryder Cup year. His bid to qualify for the 2010 match was undermined by a rib injury and last year he suffered with a toe problem that contributed to a season of under-achievement. He was showing signs of good form at the end of last year and the chance of gathering momentum has gone. At 34 he should be in the prime of his career, but Casey now faces the prospect of again playing catch up and dealing with additional pressure to perform at his best when he is able to compete again”
"I've always played well in the desert and the Abu Dhabi HSBC Golf Championship is one of my favourite events of the year, so I will particularly hate sitting out that one," added the English golfer.
"The good news is that the experts I've seen say I don't need surgery and, having already started my rehabilitation exercises, I should be back hitting balls in a few weeks."
A rib injury meant Casey failed to qualify for the last Ryder Cup and he was controversially not given a wild-card by captain Colin Montgomerie despite being in the world's top 10 at the time.
Last season he suffered from "turf toe" - a condition associated with American football or rugby players.
- Tour wins: PGA 1, European PGA 11, other 1
- Best result in majors: Masters T6 2004, US Open T10 2007, the Open T3 2010, PGA T12 2010
He said: "There were times during the summer where I could barely walk round the course, never mind play the kind of golf I know I am capable of."
The Arizona-based Casey lost his PGA Tour card in America after finishing outside the top 125 on the money list, but his world ranking means he is still eligible for golf's big events once he is fit.