All the baseball teams are identified by their city but never by their nicknames. Even the home team uniforms, which should have the team nicknames, list the city instead. The reason is because the commissioner of baseball, Happy Chandler, would not sanction the movie because of the cheating element in the movie. So 20th Century Fox could not use the the name of the teams or even use cameo baseball player walk ons like the studio wanted to do.
Many of the baseball scenes were filmed in the old Wrigley Field. Not the famous Wrigley Field in Chicago, but the former minor league Wrigley Field in Los Angeles. It was the home of two former minor league teams in the Pacific Coast League, the Los Angeles Angels and the Hollywood Stars. It was also the home field of the new American League expansion team Los Angeles Angels for their initial 1961 season. Wrigley Field was also the venue for several other baseball movies, as well as the venue for the old TV show "Home Run Derby".
When manager Dolan asks Vernon what his name is he briefly scans the outfield fence and see's a sign for Kelly Tires and tells Dolan that his name is Kelly. While this brief scene was in the film when it was released for TV in the 1960's it has now been cut from the film.
Although St. Louis at this time had a team in both Major League Baseball leagues. National League team is St. Louis Cardinals and American League was the St. Louis Browns. The cities in which the unnamed St. Louis opposing teams, plays are cities with teams in both leagues or with a National League team only.
At the time this movie was filmed, major league baseball had been integrated for two seasons. However, there are no African American ballplayers in the cast or even in the stock footage. The only African-American, was in a cameo scene as a janitor, that saw Kelly's "salve" over Monk Lanigan's hair
'crackle' he immediately said "I need a drink" and quickly left.