Jacksonville Jaguars linebacker Myles Jack has been placed in the concussion protocol after exiting Thursday night's win against the Tennessee Titans, the team announced.
Jack appeared to take a knee directly to his head while attempting to make a backfield tackle toward the start of the second half.
The 24-year-old is a key leader of Jacksonville's talented defense. He racked up a half-sack and nine tackles over the first two games this season.
With Jack sidelined, Najee Goode entered for the Jaguars, playing alongside Quincy Williams and Leon Jacobs.