American Dustin Johnson has withdrawn from the Masters because of a tweaked back.
The news was announced Tuesday, and Johnson explained the injury on his Twitter account.
"First I have to apologize to the fans and sponsors," he tweeted. "With heartfelt regret, I won't be playing in the Masters due to a tweaked back. #imsorry
"You have no idea how much I wanted to walk the fairways at Augusta and fulfill what I've been practicing for!! I'll have to root my buddies!"
Johnson, the 12th-ranked player in the world, finished tied for 38th at the Masters in each of the last two years. His career-best finish was a tie for 30th in 2009, his first appearance in the tournament.
The 27-year-old hasn't played since the WGC-Cadillac Championship in early March, when he finished tied for 35th. He has three top-10s this season, but also withdrew from the Humana Challenge in January because of back problems.