Brian's Song is a 1971 ABC Movie of the Week that recounts the details of the life of Brian Piccolo (played by James Caan), a Chicago Bears football player stricken with terminal cancer after turning pro in 1965, told through his friendship with Bears teammate Gale Sayers (Billy Dee Williams). Piccolo's and Sayers's sharply differing temperaments and racial backgrounds made them unlikely to become as close friends as they did, including becoming the first interracial roommates in the history of the National Football League, and the film chronicles the evolution of their friendship, ending with Piccolo's death in 1970. The production was such a success on ABC that it was later shown in theaters by Columbia Pictures, with a major premiere in Chicago; however, it was soon withdrawn for lack of business. Critics have called the movie one of the finest telefilms ever made. A 2005 readers poll taken by Entertainment Weekly ranked Brian's Song seventh in its list of the top "guy-cry" films ever made.
The movie is based on Sayers's account of his friendship with Piccolo and coping with Piccolo's illness in Sayers's 1970 autobiography, I Am Third. The film was written by veteran screenwriter William Blinn, whose script one Dallas television critic called "highly restrained, steering clear of any overt sentimentality [yet conveying] the genuine affection the two men felt so deeply for each other."
Although based on a true story, the film does include some fictional scenes. For example, the head coach, George Halas (played by Jack Warden), tells Sayers that he wants to bench Piccolo when he suspects that there may be a problem affecting his performance. He later learns of Brian's cancer. In reality, Jim Dooley was the head coach at that time, as Halas had retired from the position following the 1967 season.
(Summary from Wikipedia)