(Reuters) - Nine-times PGA Tour winner Stuart Appleby has undergone back surgery for a herniated disc and will be out of action indefinitely.
Appleby, 43, who has not played since mid-February, has endured back problems for much of his career.
"No idea when I'm back as I don't know or anybody knows how long it takes to get 100 percent," he told Reuters.
The Australian is one of only six players to have shot 59 on the PGA Tour.
He was not exempt for next month's Masters, after finishing 31st on the tour's points list last year.
The top 30 clinched invitations to Augusta.
Reporting by Andrew Both in Cary, North Carolina; Editing by Greg Stutchbury