The PGA Tour made the announcement Friday just before Matsuyama was scheduled to start his second round. Tour officials were unable to say whether Matsuyama has been vaccinated.
“I will take all the necessary precautions to ensure the health and safety of all others,” he said in a statement. “I appreciate and thank everyone for their concern in advance. I look forward to full recovery and returning to competition as soon as possible.”
Matsuyama shot an even-par 72 on Thursday, playing with PGA Championship winner Phil Mickelson and Rickie Fowler.
Mickelson and Fowler were informed of Matsuyama’s positive test shortly before they began play Friday. According to the PGA Tour’s COVID-19 protocols, Mickelson and Fowler were not subject to contact tracing.
At least 35 players have had to withdraw because of a positive test and Matsuyama is the fifth in the middle of a tournament since the testing program began last June.
In two weeks, the world’s top golfers will no longer be required to test for COVID-19. The final PGA Tour event for testing, not including the majors, will be the Barbasol Championship on July 15-18.