“This two-minute preview should put Bears’ fans in the mood to watch the “A Football Life” film on Dick Butkus and Gale Sayers tonight at 9 p.m. on NFL Network.

There are some vintage clips of their greatness narrated by some familiar voices. NFL Films legend John Facenda labels Butkus “Football’s dooms-day machine.”

Jack Brickhouse, in an old Bears highlight film, calls Sayers, “Galloping Gale, carrying the mail.”