Tiger Woods is to miss the Masters for the first time in 20 years, Phil Mickelson is in serious doubt and Adam Scott's odds have shortened.
Bookies cut defending champion Scott's odds to A$8.50 to claim another green jacket at Augusta National on Sunday week after four-time champion Woods was ruled out after undergoing back surgery for a pinched nerve.
The Australian is second favourite behind Rory McIlroy (A$7.50) with countryman Jason Day (A$15) equal third and their odds will surely drop further if three-time champion Mickelson (A$15) follows Woods in withdrawing after being forced to quit during last week's Texas Open due to a back muscle strain.
Woods, a 14-time major winner, released the news of his microdiscectomy surgery on his website.
"After attempting to get ready for the Masters, and failing to make the necessary progress, I decided, in consultation with my doctors, to have this procedure done," Woods said.
"I'd like to express my disappointment to the Augusta National membership, staff, volunteers and patrons that I will not be at the Masters.
"It's a week that's very special to me. It also looks like I'll be forced to miss several upcoming tournaments to focus on my rehabilitation and getting healthy.
"This is frustrating, but it's something my doctors advised me to do for my immediate and long-term health."
The 38-year-old has been suffering from back spasms since the US PGA tour playoffs of 2013, with the issue resurfacing over the last few months.
Woods has played in every Masters since 1995, when he was an amateur.
His only missed cut came the following year, still as an amateur, before he demolished the field in 1997, his first major championship as a professional, winning by a record 12 shots.
He also triumphed at Augusta National in 2001, 2002 and 2005.
Since his last victory at Augusta, Woods has seven top-10 finishes in eight appearances and six top-5s, including last year, when he tied for fourth, four strokes behind Scott.
Woods is still chasing Jack Nicklaus' record of 18 major championships and Sam Snead's 82 PGA tour wins. He sits at 14 and 79 wins respectively.
"It's tough right now, but I'm absolutely optimistic about the future," Woods said.
"There are a couple (of) records by two outstanding individuals and players that I hope one day to break.
"As I've said many times, Sam and Jack reached their milestones over an entire career. I plan to have a lot of years left in mine."
Mickelson on Tuesday told officials he would not be able to play in Wednesday pro-am for the Houston Open, but he remains in the draw for tournament which gets underway on Thursday.
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