Kyle Busch and Clint Bowyer will be without their crew chiefs in Saturday night’s playoff race at Richmond Raceway.

Adam Stevens, of Busch’s No. 18 Joe Gibbs Racing team, and Johnny Klausmeier, of Bowyer’s No. 14 Stewart-Haas Racing team, will each serve a one-race suspension in addition to being fined $20,000. The penalty stems from there being two lug nuts not safe and secure on their respective race cars after the Southern 500 in Darlington.

Jacob Canter will serve as Busch’s interim in the Federated Auto Parts 400. The winless Busch is 10th on the playoff grid, seven points above the cutline.

Greg Zipadelli, the competition director of SHR, will serve as Bowyer’s interim crew chief. It will be the second time this season Zipadelli has filled in for Klausmeier because of a lug nut penalty, the other race being one month ago at Michigan.

Bowyer is tied with teammate Aric Almirola for the final spot on the playoff grid.

Other penalties assessed for Darlington include two other crew chiefs fined for having one lug nut not safe and secure. Race-winning crew chief Rodney Childers with Kevin Harvick’s team and Chad Knaus of William Byron’s team were each fined $10,000.

In the Truck Series, Kevin Bellicourt, the crew chief for Derek Kraus, was fined $2,500 for one lug nut not being safe and secure on the No. 19 truck.