The Oakmont Country Club golf course in Pensylvannia, venue of this year’s U.S. Open, is proving to be as difficult as Phil Mickelson said it would be just a few days ago.

U.S. Open Caddie Falls, Breaks Ankle During Practice Round AT OaKMONT

Amateur golfer Chris Crawford, who is playing in his first major tournament, watched his second string-caddie Bill Henaghan go down after injuring himself on the course on Tuesday during a practice round for the Open. As Australian Jason Day was lining up his shot on the 6th hole, Crawford’s caddie slid down a grass slope into a bunker right behind the PGA Championship winner, breaking his ankle in the process.

And yet, despite the great amount of pain he surely felt, Henaghan did not forget proper golf etiquette and suppressed his cries until Day, the World No. 1 and favorite to win the U.S. Open, finished his shot.

“I’ve snapped my ankle but go ahead Jason,” posted golf writer Benjamin Everill on his Twitter account, recounting the caddie’s words. “I’ll be okay!”

Day, however, stopped preparing his shot and decided to help the caddie instead of completing his round.

Pittsburgh Steelers team doctor Jim Bradley was walking with the group and evaluated the caddie.

“The guy just broke his ankle. It was pretty obvious what had happened,” Bradley said, according to Golf Channel.

As Crawford’s “Tuesday caddie” recovers, the young golfer must now quickly find a replacement before the tournament kicks off on Thursday. Hopefully, this incident won’t scare off too many other caddies.

Day, 28, also shared this photo on Twitter of Crawford and his caddie after the latter had finished being attended to:

OAKMONT, PA – JUNE 14: Christopher Crawfords’ caddie gets medical attention after injuring himself during a practice round prior to the U.S. Open at Oakmont Country Club on June 14, 2016 in Oakmont, Pennsylvania. (Photo by Ross Kinnaird/Getty Images)

Five-time major champion Phil Mickelson has declared Oakmont Country Club in Pennsylvania, the location of next week’s US Open, as the most difficult golf course he has ever played on.

Phil Mickelson Says Next Week’s US Open Venue Oakmont Is ‘Hardest Ever’

“I played Oakmont the last two days. It truly is, I think, the hardest golf course we’ve ever played,” Mickelson told reporters in Memphis ahead of the FedEX St. Jude Classic.

“They let the rough grow long — if it’s wet they’ll leave it like that, if it’s dry they’ll thin it out because less balls will hit the fairway.”

Oakmont is known as a tough test that balloons scores. At 7,200 yards, it’s one of the shortest tracks the U.S. Open plays.

“The course stands on its own,” says USGA executive director and CEO Mike Davis, who has set up the last 27 U.S. Open courses. “Anyone wondering how this year’s Open here compares to the last time it was here can expect a lot of sameness. Every hole is exactly the same yardage as it was in 2007.

The last time it hosted a US Open in 2007, Argentine Angel Cabrera won with a five-over total of 285.

Mickelson, who will turn 46 on June 16 just three days after the tournament begins, will seek his first US Open trophy after finishing second six times.

“A lot of golf courses, when it challenges you tee to green the way Oakmont does, it usually has a little bit of a reprieve on the greens,” Mickelson said.