Tiger Woods and Hank Haney had worked together since 2004
Tiger Woods' swing coach Hank Haney has resigned, leaving the world number one without one of his top advisers as he tries to rebuild his game.
Haney said in a statement he had enjoyed working with Woods but believed it was now time for him to step aside.
"I will always look back upon our past half-dozen years together as my best days in professional golf," he said.
Woods withdrew from the final round at the Players Championship in Sawgrass last weekend, suffering neck spasms.
Haney, who starting working with Woods in 2004, added: "It would be a dream of any coach to have a student like Tiger Woods and for me it has come true.
"Just so there is no confusion I would like to make it clear that this is my decision.
"I know Tiger Woods will be successful in the future no matter who helps him."
There had been speculation during last week's PGA tournament in Florida that Woods was about to leave Haney, rather than the other way round.
Haney, 54, took over the role previously occupied by Butch Harmon six years ago. He persuaded Woods to switch from an upright golf swing to a flatter one, with a less pronounced wrist cock.
Woods' withdrawal from the Players Championship on Sunday was his first from a tournament since the Nissan Open at Riviera in 2006, and came hot on the heels of his missed cut at Quail Hollow with the highest 36-hole score of his career.
Haney was right by Woods' side as he prepared to compete in the Masters after revelations of extra-marital affairs shattered his image during the winter.
He tied for fourth at Augusta but has failed to kick on since and was tied for 45th when pulling out at Sawgrass.
Haney added: "As we all know, Tiger has been through a lot in the past six months and I really believe that given the chance, mind-free and injury-free, we will all see Tiger Woods play once again like we all know he can."
Woods plans to have an MRI scan imminently to get to the bottom of the neck pains which first flared up two weeks before the Masters.
He is unsure whether he will be able to compete in the US Open at Pebble Beach from June 17.
"For me not to play all 18 holes, that was as angry and as frustrated as I've been in a long time," said Woods.
"I've dealt with other things in my life where people said that I was pretty much done and come back. So the whole idea is just to keep fighting every day. It's all I can do."