In a stunning and seismic development for the sport of golf, one of the highest-profile players the PGA Tour never fathomed it would lose to LIV Golf bolted for the rival Saudi-backed tour on Thursday for a reported multiyear deal that could pay him about $500 million.

Jon Rahm, the 29-year-old Spaniard who’s consistently pledged his allegiance to the PGA Tour and even mocked the 54-hole, no-cut format of LIV Golf, suddenly changed his mind.

And the sight of him posing for pictures on Thursday with LIV commissioner Greg Norman while wearing a letterman LIV jacket had to be jarring to the PGA Tour, which was significantly weakened by this development.

Rahm, ranked No. 3 in the world and the reigning Masters champion, previously had been adamant about the fact that he doesn’t play golf for the money, and that legacy, playing against the best players in the world in PGA Tour events that have been the fabric of the sport are what drives him.

Asked Thursday night in a conference call if money was the main motivator behind his decision to go to LIV, Rahm said, “It’s one of the reasons, I’m not going to lie to you. It was a great offer. The money is great. Obviously, it’s wonderful. But what I said before is true: I do not play golf for the money. I play for the love of the game and the love of golf.

“But, as a husband, as a father and as a family man, I have a duty to my family to give them the best opportunities and the most amount of resources possible and that is where that comes in.’’

Rahm has earned $77 million as a pro and is a two-time major championship winner.

“I’ve been very happy, but there is a lot of things that LIV Golf has to offer that were very enticing,’’ Rahm said. “The past two years there’s been a lot of evolving in the game of golf and things have changed a lot and so have I. Seeing the growth and evolution and the innovation is something that’s captured my attention and that’s why we’re here today.”

This blockbuster development comes just 25 days before the Dec. 31 deadline for the PGA Tour and Saudi Arabia’s Public Investment Fund try to finalize their June 6 “framework agreement’’ to become commercial partners in a for-profit enterprise, along with the European tour. Where that stands now and what this Rahm deal means to it is anyone’s guess.

Rahm’s addition to LIV gives the tour seven of the last 14 major championship winners on its roster.

“LIV Golf is here to stay,” Lawrence Burian, the COO of LIV Golf, said in a statement, seemingly thumping his chest.

The PGA Tour said in a statement that its focus remains on “unifying the game for our fans and our players,’’ adding, “We can’t speak for decisions that any individual players might make but based on the momentum of the past season and strength of the PGA Tour, along with the accelerated interest from and negotiations with a number of outside investors, we are in position to make our players equity owners and further allow the tour to invest in our members, invest in our fans and continue to lead men’s professional golf forward.”

The PGA Tour has banned its players who’ve defected for LIV from playing in PGA Tour events, but that doesn’t include the four majors, which are separate entities.

Rahm remains eligible for the majors for the next five years — and the Masters for life and the U.S. Open until 2031 as a past champion.

But the question is how the move affects his eligibility for the Ryder Cup.

The DP World Tour, which runs the European Ryder Cup team, stripped Henrik Stenson of his captaincy for last year’s Ryder Cup when he joined LIV.

Rory McIlroy, one of the loudest opponents of LIV, talking with Sky Sports on Thursday, predicted that the European powers that be will be forced to soften that stance.

“It’s hard to sit here and criticize Jon because of what a great player he is,” McIlroy said. “Jon is going to be in Bethpage in 2025 [for the next Ryder Cup]. Because of this decision, the European tour is going to have to rewrite the rules. There’s no question about that.”

PGA Tour Commissioner Jay Monahan was scheduled to meet this week with Yasir Al-Rumayyan, the head of the PIF, but the meeting was delayed until next week. It’s not known if that meeting remains on or how Rahm’s announcement affects the negotiations.