Chicago Bears coach George Halas, right, shakes hands with halfback Gale Sayers of Kansas after he signed a Chicago Bears contract Dec. 1, 1965.

Gale Sayers, halfback for the Chicago Bears, August 1966.

Gale Sayers, halfback for the Chicago Bears, 1967.

Hall of Fame Chicago Bears running back Gale Sayers (40) runs upfield in a game.

Vikings players try to tackle Chicago Bears running back Gale Sayers.

Hall of Fame Chicago Bears running back Gale Sayers (40) on the bench.

Chicago Bears Hall of Fame running back Gale Sayers (40) poses for a photo during training camp.

Hall of Fame Chicago Bears running back Gale Sayers (40) runs upfield in a Bears game.

Gale Sayers of the Chicago Bears is shown in an action pose in Chicago, Ill., in Sept. 1968.

Gale Sayers (40) of the Chicago Bears grinding out yardage against the Green Bay Packers.

Chicago Bears Hall of Fame running back Gale Sayers (40) runs up field during game against the San Francisco 49ers.

Chicago Bears Gale Sayers #40 is seen in action against the Green Bay Packers.

Chicago Bears Gale Sayers #40 is seen in action against the Green Bay Packers.

Chicago Bears Hall of Fame running back Gale Sayers (40) runs upfield during an NFL game against the Green Bay Packers.

Running back Gale Sayers #40 of the Chicago Bears relaxes during a photo shoot.

Gale Sayers, football player for the Chicago Bears, 1970.

Chicago Bears running back Gale Sayers rests on the sidelines at Wrigley Field.

Chicago Bears running back Gale Sayers #40 of the West watches from the bench against the East in the NFL Pro Bowl.

hicago Bears running back Gale Sayers #40 of the West races upfield against the East in the NFL Pro Bowl.

Gale Sayers, right, and Dick Butkus are seen before an NFL football game between the Chicago Bears and Pittsburgh Steelers in Chicago.

Chicago Bears Hall of Fame running back Gale Sayers poses for his NFL ProLine Profile card.

Gale Sayers visits Halas Hall - June 2014