Henrik Stenson has labelled the U.S. Open golf's hardest major and is braced for an Erin Hills course he feels is likely to have been "tricked up" by the United States Golf Association.
Stenson joined the ranks of major winners with a thrilling Open Championship triumph over Phil Mickelson at Royal Troon in July last year.
The Swede's best result at the U.S. Open was tied fourth at Pinehurst in 2014 and the world number six knows the game's elite are likely to encounter a typically demanding course set-up in Wisconsin this week.
"As always, the USGA likes to trick it up a little bit at times, and if you go off track, then you're going to notice that that's not the place to be in a lot of areas," he said of the thick rough.
"Golf at the U.S. Open has always been a bit harder [than] at the Open or any of the other ones. We know Augusta has got the challenges, and the Open you've got the weather.
"The U.S. Open you normally play on golf courses that are tricked up just to the limits, sometimes over the limits and sometimes just underneath. So it's certainly a tiring week. But it's all worth it if you stand there with the trophy on Sunday."
Stenson has enjoyed a low-key preparation for the event, taking a week off in Sweden and only walking the course upon his arrival on Monday.
"Yeah, it's one of the majors, it's one of the toughest mental tests that you're going to encounter out there, and it's important to be fresh and, at least I think I've got that part," he said.
"It's important to have your mental strength and energy over the weekend, especially, if you're going to do well."
The last six majors have all been captured by first-time winners, a sequence stretching back to Jason Day's PGA Championship triumph in 2015, something Stenson attributes to the even spread of elite talent at the summit of the sport.
"I think the competition on a weekly basis is so tight out there and so tough," he said.
"It's so many players in the field that can win. Whether it's a trend or if this is going to continue or not, or if there is going to be a few guys stepping up and becoming second and third-time winners short of them having more first timers, I guess that's yet to see.
"But I think in general it's very hard to predict who is going to do well any other week. It's been like that in the last year and a half in the majors, for sure."
Stenson also had some important advice for any players or spectators prone to allergies ahead of their arrival at Erin Hills.
"One thing I forgot to say, this is hay fever heaven, and I expect any local pharmacy to sell out of antihistamines," he said.
"If you haven't gotten yours, make sure you get them quickly. I will. I forgot to take my pills this morning, and I've been sneezing about 50 times already."