Ken Comboy returned a positive test on Tuesday, prompting McDowell, who tested negative for the virus earlier this week, to pull out.
McDowell told Golfweek: “For the protection of the field, and for my own physical and mental well-being, I’m going to take a test tomorrow morning then jump on a private plane.
“I’m going to get myself out of here, home to Florida and decide whether I need to quarantine myself from my family.”
American golfer Cameron Champ has already tested positive for the virus during pre-tournament screening at the event, which starts on Thursday.
Nick Watney also tested positive immediately before his second round at last week’s RBC Heritage tournament, which marked the sport’s return following the lockdown.
Amid rising fears over the spread of the virus within the sport, the PGA Tour is expected to announce results from its full pre-tournament screening programme on Wednesday.