Thornton is dealing with a hamstring issue, Pete Sweeney of The Kansas City Star reports.
Thornton left Tuesday's practice session on a cart, and now there's more clarification on what caused the early exit. Hamstring issues can be tricky for receivers, and the timing is unfortunate with the season less than a month away. Thornton's timeline will be set once the severity of the hamstring injury is revealed. Regardless, Cyrus Allen and Jalen Royals should get more opportunities in Thornton's absence.