The 29-year-old RFK Racing driver hasn't missed a Cup race since becoming full-time in 2016.
He currently sits 21st in the championship standings, and made headlines in last weekend's Coke 600 after rolling multiple times in an airborne crash. Buescher has three top-tens this year and scored his first career pole position at Dover.
Buescher will be replaced by Zane Smith, a fellow Ford driver and NASCAR Truck Series (CWTS) title threat.
Smith has six CWTS victories with three just this year. He's also started 11 Xfinity races with two top-fives. Gateway will be his NASCAR Cup Series debut.
The team expected Buescher to return next weekend at Sonoma Raceway.
