First Came Golf’s Flash Grenade. Now, Here’s the U.S. Open.

Jon Rahm was at home last Tuesday, preparing coffee with his children underfoot, when the news arrived in a flood of text messages. Collin Morikawa glanced at Twitter and saw the word there. During breakfast at Michael Jordan’s private club in Florida, Brooks Koepka peered at a television and glimpsed a headline.

What was clear Tuesday — one week after the PGA Tour said it intended to join forces with the Saudi wealth fund whose LIV Golf league had fractured the sport — was that the deal Rahm, Morikawa and Koepka heard about in real time had been golf’s version of a flash grenade: stunning, staggering, disorienting.

And now, the effects lingering, they need to play the U.S. Open, a major tournament, which will begin Thursday at Los Angeles Country Club. Some escape, huh?

“I think there’s more guys that are puzzled about what the future holds,” Jason Day, who had a stint as the world’s top-ranked player soon after he won the 2015 P.G.A. Championship, said in an interview by a practice putting green.

“Some guys are emotional, I think, on both sides, which is very much understandable,” added Day, a PGA Tour fixture who turned professional in 2006. “I think we’ve just kind of got to let things settle and see where things are spread out on the table once we kind of know where things are progressing.”

It is hardly an optimal outlook just before the third men’s major championship of the year. But it is a pervasive one, and it will assuredly aid the United States Golf Association’s preference for Opens that compel players to use their minds as much as their clubs.

No Open in recent memory may demand more compartmentalization from the field.

“There’s a lot of not-answered questions,” Rahm, who opened the 2023 majors cycle with a victory at the Masters Tournament in April, said on Tuesday. “It’s tough when it’s the week before a major. Trying not to think about it as much as possible.”

For many of the elite players who could contend for the trophy this weekend in Los Angeles, turbulence in their professional lives, aside from driving, chipping and putting, has been historically scarce.

The PGA Tour was unchallenged as the world’s premier circuit for most of a period that began during Lyndon B. Johnson’s presidency, and the players who kept their tour cards were rewarded handsomely for performing well in events from Torrey Pines in San Diego to Sea Pines in Hilton Head Island, S.C.

LIV’s thunderous emergence last year proved a most severe test of the tour’s supremacy and cast a haze over professional golf. For the first time in generations, the PGA Tour was not the unrivaled signature show in American men’s golf.

Now, with the PGA Tour and LIV poised to amass their moneymaking ventures inside one new company led by the tour commissioner and chaired by the Saudi wealth fund’s governor, the dimensions of professional golf are hazier, even for the sport’s biggest names.

Will LIV exist in a year’s time? How might players who defected from the tour to LIV be allowed to return? Should golfers who remained devoted to the tour be compensated for their loyalty? And what about all of that money, said to be $100 million or more in some instances, that the wealth fund promised LIV golfers?

The deal emerged from seven weeks of secret talks that began with a WhatsApp message on April 18, continued in London, Venice and San Francisco, and culminated in an announcement in New York last Tuesday. Much about the framework agreement, though, is unclear, with bankers and lawyers still rushing to fill in blanks on matters as weighty as asset valuation. Golf executives have suggested that months could pass before the deal closes, and some are privately acknowledging that the shoals before and beyond a closing may not be easy. (“I don’t have enough information about the deal yet to have an unfavorable or favorable view about it,” Patrick Cantlay, a player who is on the PGA Tour’s board, said on Tuesday.)

In the meantime, some players suggested that they would simply settle for an answer, or answers, to their most essential questions.

“We all want to know the why,” Morikawa said. “We’re so interested in the why. For us, for me right now, it’s just like what’s going to happen? I don’t know. But we always want to know that why answer — like, what’s the purpose behind it? But I think there’s so many different parties involved that there’s too many answers to really put it into one underlying umbrella.”

Substantive answers are unlikely to emerge between now and Thursday’s first tee shots, leaving players to wonder and worry ahead of a tournament that can earn any one of them a spot in history.

“There’s not really a part of your game in any major championship, let alone a U.S. Open, that can really be in doubt,” Rahm said. “You’re going to need to access every single aspect of your game to win a championship like this. I think it becomes more of a mental factor, not overdoing it at home. You can never really replicate U.S. Open conditions.”

Koepka, among the finest major tournament golfers ever, signaled that he had tried to excise any talk of the deal during his preparations for a course he played years ago, and primarily remembered for the Playboy Mansion’s presence on the back nine.

“There’s four weeks a year I really care about and this is one of them and I want to play well, so I wasn’t going to waste any time on news that happened last week,” said Koepka, the LIV star who tied for second at the Masters in April and then won the P.G.A. Championship in May near Rochester, N.Y.

Last Tuesday, he recalled, he saw the news and then went out to practice.

The sport itself, after all, is to come center stage on Thursday, and the questions are not fading — or being answered — this week or next or the next.

“There is potential of it being a really, really good thing for golf,” Day said. “But I feel like it’s too early to kind of even say anything like that because you just don’t know where things are going to fall.”

For now, he said, “I’m trying to win a tournament.”

On that much, PGA Tour and LIV golfers agree — once they stop thinking about last week.