FILE PHOTO: Aug 11, 2023; Memphis, Tennessee, USA; Byeong Hun An watches his tee shot on the 17th hole during the second round of the FedEx St. Jude Championship golf tournament. Mandatory Credit: Christopher Hanewinckel-USA TODAY Sports/File Photo
An, who is 53rd in the world rankings, tested positive for a substance prohibited by the World Anti-Doping Agency contained in a cough medicine available over the counter in his native Korea, the PGA Tour said.