Defending champion Phil Mickelson has withdrawn from next week's PGA Championship in Tulsa, Oklahoma, tournament organisers say.
The American, 51, became the oldest major winner in history last year when he won the PGA at Kiawah Island for his sixth career major title.
He has not played since February after criticism of his comments about the Saudi-backed LIV Golf series.
He subsequently missed the Masters for the first time in 28 years.
Mickelson lost multiple sponsors and saw his reputation tarnished after he criticised the Saudi regime, yet sought to use involvement with a Saudi Arabia-backed golf super league to gain leverage over the PGA Tour.