Masters champion Hideki Matsuyama withdrew prior to his second round at the Rocket Mortgage Classic after testing positive for COVID-19.

“It’s disappointing to receive this news and have to withdraw from the Rocket Mortgage Classic,” Matsuyama said in a statement. “I will take all the necessary precautions to ensure the health and safety of all others. I appreciate and thank everyone for their concern in advance. I look forward to a full recovery and returning to competition as soon as possible.”

Matsuyama shot 2-under 70 in the first round, while grouped with Phil Mickelson and Rickie Fowler. Mickelson and Fowler, who were not subject to contact tracing, according to the Tour, are playing as a twosome on Friday afternoon.

Matsuyama will have its "full support throughout his self-isolation under CDC guidelines," the Tour stated.

It is unclear how this will affect Matsuyama for The Open Championship in Sandwich, England. A player who tests positive for COVID-19 can return to competition in 10 days, per Tour rules. They can return sooner if there are no symptoms and consecutive negative tests, which was the case for Jon Rahm, who tested positive at the Memorial Tournament and was able to return before the 10-day period in preparation for the U.S. Open, which he won.

Ten days from Friday would be the Monday of Open Championship week. The R&A, however, runs The Open and has strict COVID-19 protocols, including bubbles.

It was also unclear if Matsuyama was experiencing symptoms from the coronavirus or if he was part of contact tracing, which is required for those who are not fully vaccinated.