The white football seen in the warm-ups for the night game at the end of the film was used in the NFL for such games from 1929 to 1955. It was considered to be more visible to the players and fans than the typical brown football. By 1956 better stadium lighting, especially needed for television, made the white football obsolete.
The coin-op boxing game played in the film is "K.O. Fighters" made by the National Novelty Company of Minneapolis, Minnesota c. 1926-28. New, it cost $225 (about $3,500 in 2021). In perfect, restored condition, this machine could sell for $6,000-10,000. A more modern version, the 1960s game Rock 'Em Sock 'Em Robots, had a cameo in the 2002 film Doce Lar (2002).
Kenny Washington, who plays Benny, played college football at UCLA on the same team with Jackie Robinson and future actor Woody Strode. He and Strode were two of the first black players in the NFL; Washington played for the L.A. Rams from 1946 - 48. He had been out of football for a year when he appeared in this picture; he makes a one handed, over-the-shoulder catch during practice without a scene cut or a stunt double.
Making his film debut is Elroy 'Crazylegs' Hirsch, then a first year member of the Los Angels Rams (portraying a backfield member of The Chiefs). He is called out by The Chiefs' Coach Lenahan as "Hirsch". Elroy later would star in his film bio, Crazylegs (1953) and the prison saga, Fuga Desesperada (1955), which introduced the classic song "Unchained Melody". But, perhaps, his best-known film role was as the co-pilot in Entre a Vida e a Morte (1957), the character spoofed by Kareem Abdul-Jabbar in its parody Apertem os Cintos, o Piloto Sumiu (1980).