A frustrated Roy McIlroy walked off the course directly to his car and withdrew from the Honda Classic on Friday morning during the second round in Palm Beach Gardens, Fla.
McIlroy, the world No. 1-ranked player, hit his second shot into the water on the par-5 No. 18, his ninth hole of the day, and called it a day at the Champion Course at PGA National.
"There's not really say much I can say, guys," he said to reporters in the parking lot. "I'm not in a good place mentally, you know?"
McIlroy, the defending champion, was struggling at 7 over after a double bogey on the 11th, a bogey on No. 13, a triple on the 16th after hitting two shots in the water and a bogey on No. 17. He had opened the tournament with a 70 on Thursday.
McIlroy said his problems weren't injury related but indicated his concerns were more about his swing.
"I really don't know what's going on," McIlroy said.
McIlroy's equipment switch from Titlelist to Nike this year has raised questions about his game. He missed the cut in Abu Dhabi in his first start and was eliminated in the first round of the WGC-Accenture Match Play Championship last week.
Even though McIlroy said he was fine physically, a statement from PGA Tour media said McIlroy withdrew because of severe wisdom tooth pain affecting his concentration.
According to the PGA Tour's withdrawal policy, "During a round, a player may withdraw because of injury or other disability which requires medical attention or serious personal emergency. The player shall notify the PGA Tour tournament director or a PGA Tour Rules Official of his reason for withdrawal, and within a period of 14 days submit written evidence supporting such reason to the commissioner."
McIlroy, who has a home in nearby Jupiter, is scheduled to play next week in the WBC-Cadillac Championship at Doral.