The winners of the first two majors of the year - Rahm claimed his second major title at the Masters in April and Koepka bagged his fifth at the PGA Championship last month - were among the many blindsided by the shock announcement last week that the PGA Tour and DP World Tour would join forces with the Saudi Public Investment Fund.

The deal is being billed as one that will end the bitter rift that erupted when the PIF-funded LIV Golf breakaway league launched in October 2021.

But the merger has already drawn scrutiny from US lawmakers, and with nothing official and few details released of how the rapprochement will unfold, players arriving at Los Angeles Country Club for the 123rd US Open almost uniformly said they were just trying to shut out the politics and focus on the task at hand.

"Well, there's a lot of not-answered questions," world number two Rahm said Tuesday. "It's tough when it's the week before a major. (I'm) trying not to think about it as much as possible."

Rahm said the sudden revelation from PGA Tour officials, including commissioner Jay Monahan, who had vilified LIV as a Saudi sportswashing scheme poaching stars to play in a substandard format, couldn't help but raise doubts about the way forward.

"I want to have faith that this is the best thing for all of us, but it's clear that that's not the consensus," Rahm said. "I think the general feeling is that a lot of people feel a bit of betrayal from management.

"I get the secrecy. It's just not easy as a player that's been involved, like many others, to wake up one day and see this bombshell. That's why we're all in a bit of a state of limbo because we don't know what's going on and how much is finalized and how much they can talk about, either."

"Whether I agree with it or not, thanks to the PGA Tour, they give me a platform to play golf at the highest level, and after taking advantage of that possibility, I'm in a situation where my family and my kids don't have to struggle financially ever, and I don't know how many generations I can help if I do it properly," he said.

"I'm in a very high state of privilege in this world. I can do what I want. I can do what I love for a living. I have a blast every single day."

While another layer of uncertainty is the last thing Rahm wants to see at a US Open, Koepka said his ability to shut out distractions is one of his main advantages at a major championship.

"I enjoy the chaos," Koepka said.

"The more chaotic things get the easier it gets for me. Everything starts to slow down and I am able to focus on whatever I need to focus on while everybody else is dealing with distractions, worried about other things."

Rahm and Koepka are among the favourites this week, along with world number one Scottie Scheffler, third-ranked Rory McIlroy and reigning British Open champion Cameron Smith.

All the ingredients

Koepka's PGA Tour triumph at Oak Hill made him the first LIV golfer to win a major title, and signalled his return to top form in the wake of 2021 right knee surgery that he once feared would derail his career.

Now he's eager to challenge for a third US Open title, to go with those he won in 2017 and 2018, and the tougher the US Golf Association makes it, the better he'll like it.

"I just feel like I can outlast everybody when it comes to having to par things to death," Koepka said.

Rahm said the LA Country Club North Course, hosting a US Open for the first time and an unfamiliar layout for most in this week's field, can provide just such a test, even though at first glance it doesn't resemble the usual US Open course.

"It is a US Open. Fairways and greens, hopefully two-putt and move on," Rahm said of what will be required. "I think it's deceptively wide. Those fairways look bigger than they play. You still need to strike it really well tee to green to be able to give yourself some looks at birdie.

"It makes you think," added Rahm, whose win at Augusta National was one of his four PGA Tour victories so far this year. "It's got everything. It's got all the ingredients to be a great week."

'Double-digit' target

Koepka said he was halfway to his goal for major titles and hopes to add one more at the U.S. Open in Los Angeles this week.

Koepka excels on the sport's biggest stages, finishing in a tie for second at the Masters in April before claiming his third PGA Championship.

"Double digits, that's what I'm trying to get to," the confident American told reporters at the Los Angeles Country Club.

"I don't think it's out of the question for me. The way I've prepared, the way I've suited my game for these things is going to help me.

"I'm only 33, so I've definitely got quite a bit of time. I've just got to stay healthy and keep doing what I'm doing."

As to whether he plans to rejoin the PGA Tour when eligible to do so next year and if he would advocate for the inclusion of LIV's team golf concept, he declined to speculate.

"I'm not going to go into the future. I don't have a crystal ball with me," he said.

"I'm just worried about the U.S. Open. If I can get to number six pretty quick, that would be nice."