English, the Tour announced on Monday morning, was tested as part of the pre-tournament screening process upon arrival at Detroit Golf Club. "I appreciate the Tour's support and I look forward to competing again after I'm fully recovered".
"I am experiencing no issues and feel great physically and was surprised and disappointed to learn of the positive test", Frittelli said, adding that he would undergo a period of self-isolation.
The two-time PGA Tour victor and world No. 135 golfer did not play in last week's Travelers Championship.
The PGA Tour implemented a new rule that players must await a negative COVID-19 test result before being allowed on tournament grounds after Nick Watney, the first Tour player to test positive after the Tour's restart June 11, interacted with other players while awaiting a test result, per Golfweek's JuliaKate E. Culpepper. He became the second player in as many days to test positive after the PGA toughened coronavirus safety measures.
English missed the Travelers Championship and was set to return to action at this week's Rocket Mortgage Classic in Detroit, but he has now been withdrawn from the tournament.
English, a 30-year-old from Georgia ranked 139th in the world, won his only two PGA titles in 2013 at the St. Jude Classic and Mayakoba Classic.
English has five top-10 finishes this season, the most recent a share of ninth at Bay Hill in March.
"We're making several adjustments to our health and safety plan as noted in the memo sent to players this morning, and we will continuously reinforce to all players, caddies, staff members and support personnel on property at PGA Tour events to adhere to social distancing and other safety professionals that further minimize risk".