England's Paul Casey is out of next week's Accenture Match Play Championship in Arizona due to shoulder trouble.
Casey, runner-up in the Match Play to Geoff Ogilvy in 2009 and Ian Poulter the following year, suffered the injury snowboarding in Colorado last month.
He hopes to have recovered from his dislocated shoulder in time for the WGC-Cadillac Championship in Miami on March 8-11.
His withdrawal brings South African George Coetzee into the 64-man field at Dove Mountain, where he will face world number one and defending champion Luke Donald unless any other players pull out before Monday's official draw.
Casey, told immediately after his accident that he probably faced two months out of action, is the second withdrawal from the first of this season's world championships.
Phil Mickelson confirmed after his victory at Pebble Beach on Sunday that he would be taking a family vacation rather than playing in an event where he has only once reached the quarter-finals in 11 attempts.
That gave Ernie Els a place after he had dropped to 65th in the world rankings and, as things stand, he will now be playing Rory McIlroy in next Wednesday's opening round.
McIlroy is currently third in the world, but is set to return to number two ahead of Lee Westwood this weekend.
Being unable to defend his Volvo Champions title in South Africa and missing the entire Middle East swing of the European Tour put a dent in Casey's hopes of returning to the Ryder Cup side this year, but the Match Play is a bigger blow given his record in the tournament and the total prize money of nearly £5.4million.
Currently 23rd in the world, he failed to qualify for Europe's side two years ago after suffering a rib injury at the start of the race and was then overlooked for a wild card by then captain Colin Montgomerie despite being ranked ninth at the time.
With Coetzee stepping up American Ryan Moore becomes first reserve. He reached the quarter-finals last year before becoming one of Donald's victims.