Panthers use sign at practice to cut down on mental mistakes

In this Thursday, July 29, 2021, photo, Carolina Panthers wide receiver Keith Kirkwood runs after a catch during practice at the NFL football team's training camp in Spartanburg, S.C. Kirkwood was hit in the neck area during practice Tuesday, Aug. 3, 2021, and was placed on a board and taken away in an ambulance. (AP Photo/Nell Redmond)

In this Thursday, July 29, 2021, photo, Carolina Panthers wide receiver Keith Kirkwood runs after a catch during practice at the NFL football team's training camp in Spartanburg, S.C., Thursday, July 29, 2021. Kirkwood was hit in the neck area during practice Tuesday, Aug. 3, 2021, and was placed on a board and taken away in an ambulance.(AP Photo/Nell Redmond)

Carolina Panthers wide receiver Terrace Marshall Jr. runs after a catch during practice at the NFL football team's training camp in Spartanburg, S.C., Tuesday, Aug. 3, 2021. (AP Photo/Nell Redmond)