The official reason: He had "severe wisdom tooth pain" that affected his concentration, the PGA announced.
He was +7 through eight holes when he hit his second in the water on his 9th hole, walked to the parking lot, and pulled out of the tournament, Yahoo!'s Shane Bacon reports.
McIlroy was cryptic after the round, saying, "I'm not in a great place mentally. I can't really say much, guys. I'm just in a bad place mentally.''
That sounds like something not golf-related is going on.
McIlroy is still ranked No. 1 in the world, but in his three tournaments this year he has missed the cut, lost in the first round of match play, and withdrawn.
This says it all:
And here he is walking off:
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