Phil Mickelson has withdrawn from next week's PGA Championship at Southern Hills.
Mickelson had been expected to defend his title in Oklahoma after he was listed in the final field for the second major of the year alongside Tiger Woods.
Lefty, 51, was one of several pros who had recently requested releases from the PGA Tour to compete in the first event of the Saudi-backed rebel league.
But Jay Monahan, the PGA Tour commissioner, decided to draw a line in the sand by denying waivers for the LIV Golf Invitational Series opener at Centurion Club next month.
Mickelson went into self-imposed exile in late February after his comments about working with the Saudis went public.
He admitted to overlooking human rights abuses as it was a once-in-a-lifetime opportunity to re-shape the PGA Tour and how it operates.
It followed comments accusing the PGA Tour of "obnoxious greed" over players' media rights and how they are handled.
In his apology statement, Mickelson said that over the last 10 years he has felt stress affecting him at a deeper level.
He said he was taking some time away from the game to focus on being the man he wants to be.
Mickelson resurfaced earlier this month and was spotted ripping some drives. He looked as if he had grown a beard.
There were rumours he had been tucked away in Montana with his wife Amy. He reportedly was also visiting Callaway performance centres ahead of his return to golf.
Last year at Kiawah Island he captured the hearts and minds of golf fans by holding off Brooks Koepka to win his sixth major. It was only two months after his 51st birthday.
The PGA of America said in a statement: