The real Jimmy Piersall disowned the movie due to its distortion of the facts. Based on the success of his autobiography and the movie, Piersall penned a second book in 1985 called The Truth Hurts, which detailed his ousting from the White Sox organization.
Left-handed Anthony Perkins had to bat and throw with his opposite hand to portray Jimmy Piersall, who was right-handed in real life.
Anthony Perkins was very apprehensive about his breakdown scene. It hadn't been rehearsed in any detail, and tensions were so high on the set between him and the crew that many thought Perkins was close to breaking down himself. He and Robert Mulligan knew that the scene would be somewhat improvised and spontaneous, but neither was sure exactly what Perkins would do when the scene needed to be shot.
It was rumoured that Anthony Perkins was in a homosexual relationship with Tab Hunter, who reportedly frequented the set. Hunter had recently been outed as a homosexual by Confidential magazine, and Paramount was reportedly uncomfortable with the association between their star and Hunter. To do damage control and help promote the film, Paramount sent Perkins and Norma Moore out on several public dates. The two would sometimes even double date in public with Hunter.
Even though Paramount was positioning Anthony Perkins as a major leading man, he made it clear that he was first and foremost an actor and wasn't interested in a lot of publicity. His intensity made him somewhat aloof from the crew, and his obvious lack of baseball skills made the ultra-serious actor the butt of many jokes. Before long the mood on the set became tense and antagonistic between Perkins and the crew. According to Norma Moore, "Tony became more and more difficult as the film went on. By the time we were in the last third or fourth of the shoot, the crew was antagonized by him. They made snide remarks about him, and he just distanced himself."