Drivers try to protect playoff positions at tricky Charlotte

Kyle Busch prepares to practice for Sunday's NASCAR Cup Series auto race at Charlotte Motor Speedway in Concord, N.C., Saturday, Sept. 28, 2019. (AP Photo/Gerry Broome)

Denny Hamlin waits in his car during practice for Sunday's NASCAR Cup Series auto race at Charlotte Motor Speedway in Concord, N.C., Saturday, Sept. 28, 2019. (AP Photo/Gerry Broome)

Brad Keselowski puts on his helmet during practice for Sunday's NASCAR Cup Series auto race at Charlotte Motor Speedway in Concord, N.C., Saturday, Sept. 28, 2019. (AP Photo/Gerry Broome)

Kevin Harvick, left, speaks with a crew member in the garage during practice Sunday's NASCAR Cup Series auto race at Charlotte Motor Speedway in Concord, N.C., Saturday, Sept. 28, 2019. (AP Photo/Gerry Broome)

Martin Truex Jr. pauses to sign an autograph for a fan during practice for Sunday's NASCAR Cup Series auto race at Charlotte Motor Speedway in Concord, N.C., Saturday, Sept. 28, 2019. (AP Photo/Gerry Broome)

Joey Logano gets into his car to practice for Sunday's NASCAR Cup Series auto race at Charlotte Motor Speedway in Concord, N.C., Saturday, Sept. 28, 2019. (AP Photo/Mike McCarn)

Pole winner William Byron sits in his car during practice for Sunday's NASCAR Cup Series auto race at Charlotte Motor Speedway in Concord, N.C., Saturday, Sept. 28, 2019. (AP Photo/Wesley Broome)