NASCAR Cup Series driver Austin Dillon tested positive for COVID-19 and will not race Sunday at the Daytona International Speedway Road Course, per Richard Childress Racing. 

Dillon self-reported the positive test after showing mild symptoms and is self-quarantining. His wife Whitney and newly born son Ace are healthy and symptom free, according to the team.

Kaz Grala has been tasked with driving the No. 3 car in Dillon's absence. It will be the Cup Series debut for the 21-year-old Grala, who has run 61 combined races in the Xfinity and Truck Series. Grala's one victory in trucks came at Daytona on the oval. He will start from the rear of the field; it is NASCAR's policy to move cars to the rear for driver changes.

In order to return, Dillon must provide two negative COVID-19 test results from tests taken at least 24 hours apart. In addition, he will need to receive written clearance to return from his personal physician. If 10 days pass from his initial positive test, NASCAR's consulting physician may review Dillon's return status. 

Back in July, Dillon took the No. 3 to Victory Lane at Texas, clinching his spot in the NASCAR Playoffs. Richard Childress Racing will need to request a medical waiver that will allow Dillon to retain his postseason eligibility. 

Dillon joins seven-time NASCAR champion Jimmie Johnson as notable drivers to test positive for COVID-19. Johnson missed only one race due to the virus.