Not putting a timetable on his return, four-time champion Tiger Woods confirmed he will not be fit for next week's Masters.
"Unfortunately, I won't be competing in this year's Masters. I did about everything I could to play, but my back rehabilitation didn't allow me the time to get tournament ready," the former World No.1 said in a statement on his official website.
Winner of 14 majors, the American has not played since withdrawing from the Dubai Desert Classic on 3 February with ongoing back spasms.
"I'm especially upset because it's a special anniversary for me that's filled with a lot of great memories. I can't believe it's been 20 years since I won my first green jacket.
"I have no timetable for my return, but I will continue my diligent effort to recover, and want to get back out there as soon as possible," Woods added.
Woods returned to action in December after a 17 month hiatus but missed the cut at the Farmers Insurance Open in January after rounds of 76 and 72 and was injured again after an opening round of 77 in Dubai the following week.
"I'd like to pass along my regrets to Billy Payne, the Augusta National membership, staff, volunteers and patrons, that I won't be there. I will be at the Champions Dinner and I look forward to seeing a lot of old friends," he said.
"Augusta National has been a very important place to me and my family for over 20 years, and while I'm disappointed, it will be good to be back there Tuesday."