Former champion Jason Day will be the first Australian out, as the world's best golfers brace for a torrid test. Officials have set up an Augusta-like challenge for the second men's major of the year, with hard and fast greens placing a premium on accuracy of approach shots at Aronimink Golf Club.

"You can make it as easy or difficult on yourself as you'd like. If you get aggressive to certain pins and short-side yourself, you're going to hit it to 20 or 30 feet at best," 2024 winner Xander Schauffele said ahead of Thursday night's first round (AEST).

"But at the same time, there's certain pockets, little fingers on the greens where you can hit a really good shot and get rewarded for it, depending on firmness, obviously.

"The greens are definitely the thing to prepare for, for this tournament. I think it will be fun to watch."

Schauffele reckons experience from Augusta National will count for little when the PGA Championship returns to the Philadelphia layout for the first time since 1962.

The course hosted the 2018 BMW Championship, but in wildly different conditions.

"There's a level of familiarity at Augusta; just being there so many times," Schauffele said.

"This is my second time on this property, and the first time it rained a crazy amount. It was lift, clean, and place every day. So hard to pull from any of that knowledge back in 2018.

"Barring that, I'm playing early on Thursday, so I'm kind of in that wave of setting the pace. Usually when you're in the afternoon wave, you can kind of see what guys are doing and get a feel of what's possible out there.

"That's at least what I do. For the most part, in the morning the greens will be a little bit softer if it's not too cold, and they're going to firm up with the wind in the afternoon.

"If you're in the fairway, you can definitely be aggressive, but if you're in the rough, this rough is pretty gnarly."

Day was the leading Aussie at the Masters, finishing tied for 12th, and will look to benefit, like Schauffele, from playing in the morning wave.

The 2015 PGA champion is playing with Americans Sam Burns and Gary Woodland, who has already penned golf's feel-good story of the year by winning the Houston Open in March, three years after undergoing brain surgery.

Day's trio hits off at 9.34pm (AEST), with fellow Australians Cameron Smith and Min Woo Lee also enjoying morning tee times.

Adam Scott, Elvis Smylie and Travis Smyth all have afternoon tee-offs.

World No.1 Scottie Scheffler is the defending champion, while the second-ranked Masters winner Rory McIlroy is bidding to become the first player since Jordan Spieth in 2015 to win the year's first two majors.

Spieth is again striving to join McIlroy as one of only six players to complete the career grand slam.