Ninety nine of the world's top 100 are among the field contesting the US PGA Championship - but world number two Phil Mickelson was almost not among them.
Mickelson had opted not to practise at Oak Hill on Wednesday but was forced to make an unscheduled visit to the course, wearing shorts and flip flops, after forgetting to officially register for the event.
The Open champion would have been disqualified if he had failed to sign in, as 2003 US PGA runner-up Chad Campbell was in the Deutsche Bank Championship in 2010. Campbell had even played his first round before the mistake was discovered.
Mickelson is among the later starters on Thursday and has been paired, as is traditional, with the other two majors winners of 2013, Masters champion Adam Scott and US Open winner Justin Rose.
Defending champion Rory McIlroy is due off at 1:25pm local time, 20 minutes ahead of Mickelson, while world number one Tiger Woods is off at 8:35am alongside 2011 winner Keegan Bradley and former Ryder Cup captain Davis Love.
Mickelson is not alone in having an eventful week so far, David Lynn's hire car breaking down after he put the wrong type of petrol in on the way back from a visit to Niagara Falls.
Lynn, a surprise runner-up to McIlroy 12 months ago at Kiawah Island, found the car did not take kindly to the cheaper grade of fuel he opted for and was forced to leave it at a service station around 40 miles from Rochester.
McIlroy won by eight shots 12 months ago but is rated a 33/1 shot to retain his title after registering just one top-three finish so far in 2013 and labelling his own play at the Open last month as "brain dead."
However, the 24-year-old has been watching videos of his victory at Kiawah to gain inspiration and is a fan of the course set up at Oak Hill.
"I love how they have set the golf course up with the graduated rough. I think it's a great idea," he said. "You're not penalised too much if you hit a shot just off line.
"I think they have set the golf course up fantastically well. It's not an overly-long golf course but you have to be really precise. You've got to hit fairways to give yourself chances going into the greens.
"I love PGA Championship golf courses because they set the golf course up so well. They are not looking to protect par. They are not bothered about people making birdies. There's going to be opportunities to make birdies out there but it's obviously a very stern test of golf."