BROOKLINE, Mass. >> Every loudmouth from Yarmouth and Masshole from Athol has descended on The Country Club this week, when 14 golfers in the U.S. Open field will face the American public for the first time since defecting to an upstart, Saudi Arabian-backed tour.

The injection of genuine international intrigue is expected to energize the legendarily obnoxious Boston sports fan and make the staid, secretive enclave look more like a Sam Adams commercial casting call.

Guys named Sully and Fitz lined the fairways and greens at the 140-year-old club during the practice rounds, ready to greet their least favorite golfers with the same reception their ancestors gave the Redcoats at Lexington and Concord.

“It’s going to be loud, and it’s going to be a lot of fun,” said defending U.S. Open champion John Rahm, who has stuck with the PGA Tour and eschewed the bigger, guaranteed paydays offered by LIV Golf.

“There hasn’t been a U.S. Open here in a very long time, so they’re hungry for it, and you can tell,” Rahm said. “It almost feels like with what’s going on in the world of golf, they almost want to show their presence even more. I don’t know exactly what to expect, but I’m really looking forward to it.”

More tentative was Phil Mickleson, a six-time major champion who is the biggest name among the LIV XIV. He said in February that Saudi regime funding the new tour had some “scary (expletive)” but still took a reported $200 million to play on it.

One of the most popular players in the world, Mickelson said on Monday that he was unsure if his supporters would abandon him.

Just in case, he buttered up the locals like a Parker House roll.

“The Boston crowds are some of the best in sports,” Mickelson said during a 25-minute media session after arriving in this Boston suburb from last week’s LIV event outside of London.

“I think that their excitement and energy is what creates such a great atmosphere,” he said. “So whether it’s positive or negative towards me directly, I think it’s going to provide an incredible atmosphere to hold this championship.”

Golf is typically the most genteel of sports, with its hushed greenside whispers and polite, muffled applause. It is rude to talk during a player’s swing; cheering a rival’s miss simply is not done.

Sill, there are exceptions.

The Phoenix Open is a beer-fueled revelry that would not be out of place in the Yankee Stadium bleachers. And here at The Country Club, the 1999 Ryder Cup erupted into a hullaballoo that lives on as “The Battle of Brookline.”

During the biennial competition between golfers from the United States and a team from Europe, doughy Scotsman Colin Montgomerie was relentlessly heckled for his resemblance to the Robin Williams-in-drag movie character Mrs. Doubtfire (as well as former New England Patriots coach Bill Parcells, nicknamed “Tuna”).

Some of the sport’s other niceties were likewise ignored, notably the American celebration after Justin Leonard’s Cup-clinching birdie on the 17th green — before José María Olazábal had a chance to putt out. The Europeans fumed.

But those antics were mild compared to what other visiting athletes have experienced in Boston.

Yankees shortstop Bucky Dent has acquired a new middle name — it rhymes with “Bucky” — for the crime of hitting a home run against the Red Sox. Brooklyn Nets guard Kyrie Irving had a water bottle thrown at him after a postseason game; he had the nerve to leave the Celtics after professing his love for the city.

NFL Commissioner Roger Goodell was hidden from view at the New England Patriots Super Bowl banner-raising in 2017, lest it trigger fans still angry over his decision to suspend quarterback Tom Brady for his role in the Deflategate cheating saga.

And just last week, Celtics fans greeted Golden State Warriors antagonist and NBA Finals opponent Draymond Green with a vulgar chant. (It also, somewhat unimaginatively, rhymed with “Bucky.”)

“Classy. Very classy,” said Warriors coach Steve Kerr, who was heckled by a Duck Boat driver — albeit amiably — while walking around town.

“That’s just Boston being Boston,” The Boston Globe explained today in a deep dive into the characteristic cold shoulder of the city’s sports fans. “Rude gestures are simply how we say ‘hi’ around here.”

The U.S. Open crowds were thick but well-behaved early in the week as golfers played their practice rounds. Two graying women discussed their online bridge matches while waiting to cross the 18th fairway. Men wearing golf shirts from their home clubs discussed business, or their latest round.

Mickelson had a handful of police walking with him on Tuesday — not unusual for one of the sport’s biggest names, even if they did seem to be on higher alert than usual. They heard only cheers as their protectee made his way around the course.

“Good stuff, Phil!” shouted Kameron Luthea, a Cumberland, Rhode Island, man who watched Mickelson tee off on No. 6 on Tuesday. “Boston loves you, Phil!”

Luthea said he became a Mickelson fan because they are both left-handed. Asked if he was troubled by the connection to the repressive Saudi regime, Luthea said carefully: “I support Phil and his golf game.”

“I like the way he plays,” Luthea said. “He’s in it to win it. He’s got no fear.”

In fact, Mickelson may have nothing to fear this week other than the punishing Country Club layout. The 51-year-old San Diegan, who turns 52 on Thursday, has won every major tournament except the U.S. Open, which bills itself as “golf’s toughest test,” finishing second a record six times.

“Don’t be killing the Boston fans,” Larry Costello, a resident of the nearby West Roxbury neighborhood, told a reporter after Mickelson came over to the gallery to greet an acquaintance. Fans took selfies and reached out with items for the golfer to sign before he headed off down the fairway to complete his round.

The gallery followed, but not before Luthea offered one last thought:

“Screw Kyrie,” he shouted to a reporter. “You can throw that in there.”