AP source: Broncos star Miller sustains serious ankle injury

Denver Broncos linebacker Von Miller takes part in drills during an NFL football practice Friday, Aug. 28, 2020, in Englewood, Colo. (AP Photo/David Zalubowski)

Denver Broncos linebacker Von Miller (58) takes part in drills during an NFL football practice Tuesday, Aug. 18, 2020, at the team's headquarter in Englewood, Colo. The superstar linebacker is so eager to end four years of frustration that he reshaped his body and his mindset in the offseason. (AP Photo/David Zalubowski)

Denver Broncos linebackers Von Miller, right, and Jeremiah Attaochu take part in drills during an NFL football practice Monday, Aug. 31, 2020, in Englewood, Colo. (AP Photo/David Zalubowski)

Denver Broncos linebacker Von Miller takes part in drills during NFL football practice Thursday, Sept. 3, 2020, in Englewood, Colo. (AP Photo/David Zalubowski)