"I needed that day off, " Woods said.
That trio and top-ranked Dustin Johnson are oddsmakers favorites for the year's last major event on a rain-softened course where length will help but second shots into tight landing areas will be critical.
In his final PGA Championship news conference as CEO, Pete Bevacqua addressed possible a headquarters move to Frisco, Texas.
Only three players are exempt from that - Patrick Reed, who won the Masters, Brooks Koepka, who won the U.S. Open and Francesco Molinari, who won the British Open last week.
Along with coverage of the featured groups, PGA Championship LIVE will provide coverage of the closing Nos. "I've kept giving myself chances this year".
"There's a lot of different layers to what Tiger has to go through to win again", said McIlroy.
Marc Leishman is next best of the Australians at two under midway through his round, while former world No.1 Adam Scott is a shot back at one under.
"Even though it's going to be softer and wet, it's got the potential for I think anybody to work their way up the board", Spieth said. "He just had his fourth back surgery, so to get to this point is a phenomenal achievement already".More news: Rangers 'on verge of signing Osijek defender Borna Barisic'
Not only is it the 100th PGA Championship - it's also the final major golf event of the year.
Englishman Tommy Fleetwood is a player who's seemingly in contention every week, yet he's still searching for his first victory on USA soil and his first major championship.
"If you're able to hit the ball well and put the ball in the right sections, you'll see a bunch of birdies".
"I feel like I'm just showing up to catch Jack Nicklaus and Arnold Palmer, I wouldn't do that".
In the search for a "modern headquarters setting" the PGA of America has been in discussions to partner with Frisco, Texas on a new headquarters and golf facility capable of more close interaction with major corporations and hosting future PGAs or a Ryder Cup.
"A lot of careers are defined on major championships".
"Since I've been playing well, and particularly since I've been playing well in the majors, I tend to look at them more".
"It will always be circled to complete the career Grand Slam, which will ultimately achieve a life-long goal for me, so certainly emphasis in my head on it, but nothing overpowering", Spieth said.