Ironically, in the scene where Ms. Grable is rehearsing dance routines over and over (as she is the understudy) in the event she is called upon to fill in for the leading lady, her friend Flo, played by Jane Wyman, utters the line "You have as much chance of going on as I have of becoming First Lady." Of course, Ms Wyman's husband, Ronald Reagan, did become President, but was remarried to Nancy Reagan by that time.
Twentieth Century-Fox had wanted to borrow Lucille Ball from RKO, but Miss Ball had no interest in playing the secondary part of Flo La Verne.
Unused in the release print, footage of Betty Grable and chorus girls performing "I'll Be Marching to a Love Song" (music by Ralph Rainger, lyrics by Leo Robin) would wind up in the all-star short subject, Hollywood Victory Caravan (1945). In the 1942 feature, a brief bit of this number, serving as the coda, was done by Miss Grable, John Payne, Victor Mature and chorus. Another deletion was a slapstick dance routine by Miss Grable and Mr. Mature which can be seen in Hidden Hollywood: Treasures from the 20th Century Fox Vaults, hosted by Joan Collins.
Fidel LaBarba , former Olympic Gold Medal Winner (1924) & World Flyweight Boxing Champion (1925-27), co-wrote the story with Kenneth Earl while working directly for Darryl F. Zanuck. The original story, named "Kid Dynamite", was loosely based on Fidel's own life at the time.
Fidel gave boxing lessons to Zanuck on a regular basis. Noted in article in February 15, 1937 Life Magazine.
Surprisingly, given her ascending popularity with moviegoers at the time, Betty Grable was billed second to John Payne in this movie. However, poster art for the picture emphasized Betty in full figure. Later that year, Miss Grable would receive top billing over Mr. Payne in their next musical, Springtime in the Rockies (1942).