Tiger Woods’s miserable golf season developed into a period of transition Monday as he announced that he will no longer work with Sean Foley, his swing coach for the past four years.

“Sean is one of the outstanding coaches in golf today, and I know he will continue to be successful with the players working with him,” Woods wrote on his Web site.

With that, Woods entered an increasingly murky future. He missed the first two majors of the year following back surgery, finished 69th at the British Open, withdrew from the Bridgestone Invitational when his back flared up and then missed the cut at the PGA Championship. A year after winning five times on the PGA Tour, he hasn’t finished better than tied for 25th in any of his eight starts, and he is ineligible for the FedEx Cup playoffs.

“With my next tournament not until my World Challenge event [in December] at Isleworth in Orlando, this is the right time to end our professional relationship,” Woods wrote.

Foley, who also works with established pros such as Justin Rose and Hunter Mahan, was a little-known instructor from Canada when he hooked up with Woods in 2010, the summer Woods parted ways with Hank Haney. A student of biomechanics with a vast array of interests — “He knows a lot about a lot,” Woods said in 2011 — Foley became something of a star in the golf community, toting his video camera with him on course, consulting with trade magazines for instructional pieces and breaking down Woods’s swing for anyone who would listen.

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Yet Foley became the first of Woods’s three professional coaches (he first worked with renowned instructor Butch Harmon) with whom Woods did not win a major.

“My time spent with Tiger is one of the highlights of my career so far, and I am appreciative of the many experiences we shared together,” Foley wrote in a statement on Woods’s Web site.. “It was a lifelong ambition of mine to teach the best player of all time in our sport. I am both grateful for the things we had the opportunity to learn from one another, as well as the enduring friendship we have built. I have nothing but respect and admiration for him.”

Woods, 38, may be at the most unstable point of a career that spans nearly two decades as the sport’s central figure. Rory McIlroy, the dashing 25-year-old Northern Irishman, is now golf’s leading man, the winner of the past two majors and the No. 1 player in the world. Meantime, Woods has become a non-factor at majors — the tournaments he considers true barometers of his game. He has been unable to play in four of the past 15 majors, missed the cut twice and has just three top-10 finishes. In his previous 19 majors, he had four wins and 13 top-10 finishes.

Now, he’s looking to find someone new to help him to return to form.

“Presently, I do not have a coach, and there is no timetable for hiring one,” Woods wrote.