Japan's Hideki Matsuyama was disqualified from the Memorial Tournament during Thursday's first round due to an illegal marking on the face of his No. 3 wood.
Matsuyama, who won his first PGA Tour title at Muirfield Village in 2014, had shot 3-over-par 39 on the front nine before he was notified of his disqualification by an official.
"One of his equipment people had applied it as an alignment aid, but it made the club non-conforming in that it could have changed the spin and other flight characteristics of the ball," the tour said on the modification, which was made using a whiteout-like substance.
It stated that an online picture of the club came to the officials' attention soon after Matsuyama teed off. Simply carrying the club in his bag would not have resulted in a disqualification, but the 30-year-old said he had used it when an official asked him at the second tee.
"He was very honest and forthright about it," said Chief Referee Steve Rintoul. "Just an unfortunate set of circumstances for Hideki for sure."
