A strong field, an unpredictable course at Players

Golfers head up the 12th fairway towards the green during a practice round for The Players Championship golf tournament Wednesday

Defending champion Jason Day, winless since his victory at The Players previous year, was 5 under through 11 holes until he dropped shots on three of his last four holes for a 70.

"I like the fact that it gives you more options than before", world No. 1 Dustin Johnson said.

The Players Championship starts Thursday on the TPC Sawgrass, which offers a $10.5 million purse — even the runner-up gets over $1.1 million — a five-year exemption on the PGA Tour, a three-year exemption to the Masters and British Open and plenty of frustration when something goes wrong.

NBC Sports' popular cable-suspended "Supra Cam" returns to The Players Championship this year, flying for 150 yards over the body of water between the 16th- and 17th-hole greens.

Many of golf's biggest names struggled to gain traction, much less maintain it.

He was playing in the same group as Rickie Fowler, the 2015 champion who also got off to a fast start until one bad shot - a really bad shot - on his 15th hole at the par-4 seventh.

"It's also the day I was married", said McIlroy, who married Erica Stoll on April 22. "Obviously there's so much water here and there's no real easy recovery from the water".

"It's close", Day said.

For Shane Lowry it was a particularly disappointing day as he fired a 76 to finish six over and miss the cut - his first since the Masters - largely thanks to two double bogeys in his round. He hasn't won since The Players past year. Hopefully, all going well, we get back on. "I feel like this is one of those places that every time I play, it only frustrates me more".

And the 37-year-old American joins 26-year-old Hughes at the top of the leaderboard after the 2016 RSM Classic victor fired a bogey-free round which included five birdies.

J.B. Holmes, Alex Noren, Chez Reavie and Jon Rahm are a shot off the pace heading into Friday's second round. Mackenzie Hughes of Dundas, Ont., who was tied for the lead after a first-round 67, fell down the leaderboard after a second-round 75.

Earlier in the week Paul McGinley had given a very blunt assessment of McIlroy's prospects with his new equipment when he said that the four-time Major victor "isn't very close at all" to reaching the peak of his powers again, saying that he will need time to bed in the new equipment.

"I feel like I'm playing really well right now", Johnson said.

"For a moment there after I lost my number one world ranking, I kind of lost the desire to be there, and I think it was just because I was mentally burnt out from everything that had gone on", said Day. Here's hoping he can produce a shot like this again in the next four days! As the saying goes, a final-hole birdie can make dinner taste better, while a late bogey can turn it sour. "But with that being said, you always got to start somewhere and try and build on it and it seems like it was a good start for me". "I averaged 311 yards off the tee while hitting mostly 2-irons", Day told AAP. He could accept this 71 just because of all that went wrong - the wedge that hit the pin on No. 1, birdie putts that spun around the holes at Nos.

England's Justin Rose is one further back, while world number one Dustin Johnson carded a one-under 71 and Luke Donald opened with a 74.