Kyle Busch and Clint Bowyer will be without their crew chiefs for Saturday night's NASCAR Cup Series race at Richmond Raceway.
Both crew chiefs will be serving one-race NASCAR suspensions after Busch and Bowyer finished Sunday's race at Darlington with two lug nuts that were either loose or missing completely.
Busch and his Joe Gibbs Racing crew will be without crew chief Adam Stevens, who has won Cup championships with Busch in 2015 and '19. Jacob Canter, one of the team's engineers, will fill in at Richmond.
Bowyer will be without crew chief Johnny Klausmeier, with Greg Zipadelli, Stewart-Haas Racing's vice president of competition, making the calls atop the pit box on Saturday night. Zipadelli was crew chief for Tony Stewart's first two Cup championships.
Saturday's race is the second of three in the first stage of the Cup playoffs. The playoff field will be cut from 16 drivers to 12 following the Sept. 19 race at Bristol Motor Speedway.
Busch enters Richmond 10th in points, while Bowyer is 13th.