Gregg is currently being treated at the Colorado Neurological Institute.
The Hall of Fame tackle was nicknamed "Iron Man" for playing in a then-record 188 consecutive games. Gregg played for the Packers during their initial glory years from 1956-1970 and won six NFL Championships. He finished his career as a Cowboy in 1971.
Gregg's 34-27 mark -- including playoffs -- at Cincinnati is the highest winning percentage in club history.
The Texas native holds a 75-85-1 mark as an NFL head coach, which also included stops in Cleveland (1975-77) and Green Bay (1984-87).