Chris Buescher will miss the maiden NASCAR Cup Series race at Gateway Motorsports Park this weekend after contracting COVID-19.
The Roush Fenway Keselowski Racing driver will be replaced in the #17 Ford Mustang by Truck Series front-runner Zane Smith.
Smith has three race wins this season and sits third in the Truck Series standings.
Buescher meanwhile is 21st in the Cup Series, and was on pole position last month at Dover Motor Speedway.
The 29-year-old is expected to return next week at Sonoma Raceway.