So what do the pros think of director of golf course management Matt Shaffer's course at Merion Golf Club? The world's No. 1 weighed in today on the subject.
"It's a great golf course," Tiger Woods said.
Woods added that whether the golf course plays dry or soft, with the latter being the most likely, doesn't really matter.
"Either one, the execution doesn't change," Woods said. "You've still got to hit good shots and get the ball in play, especially now with the rough being wet. It's imperative to get the ball in play so we can get after some of these flags and make as many birdies as we can."
"It's a real shame that we've had so much rain. I think that most people would like to see this course play firm and fast," Donald says, "and I don't think we're going to get that this week. But it's a good challenge, this course. I think if it was firm and fast, even despite the length, would hold up just as well as any other U.S. Open course."
Yet Geoff Ogilvy posted on Twitter that the course is by no means defenseless.
"Greens at least a foot faster towards the end of the day as they dried out. Closer to U.S. Open speed," he tweeted.
Former U.S. Open champion Graeme McDowell isn't convinced that Merion will be a cakewalk.
"Obviously, it's not a long golf course by yardage; it doesn't suggest that it's a long golf course," McDowell says. "Everyone is saying that it's going to be 62s and 63s on this golf course, which I kind of disagree with at the minute.
"I think there's 10 or 11 of these golf holes on this course that are as tough as any U.S. Open I've seen. I don't think it's going to be a scorefest. I think it's tough. Like I said about the greens ... they're soft and fast, which is a bad combination for Tour players."