Born in St. Louis, Missouri, Rapp signed his first playing contract out of high school in 1945 with his hometown St. Louis Cardinals. A right-handed batter and thrower, he reached the triple A level with the Columbus Red Birds in 1948, but never made it to the major leagues. After missing two seasons due to military service during the Korean War, Rapp was released by the Cardinals in 1955, and signed with the independent Charleston Senators of the American Association for the 1956 season. The experience provided him his first managing job, when, at age 27, he succeeded Danny Murtaugh as field boss of the last-place Senators. As player-manager, Rapp guided his club to only 19 victories in 59 games.
The following season, Rapp joined the New York Giants organization, and batted .302 with eleven home runs for their triple A affiliate, the Minneapolis Millers. After spending 1957 with the Louisville Colonels, Rapp became a player/coach with the Denver Bears. Denver was a New York Yankees affiliate when he joined the club in 1958, and he remained with them through 1960, by which time they were a Detroit Tigers affiliate. During three seasons with the Denver Bears, he became associated with Denver owner Bob Howsam, who would play an influential role later in Rapp’s career.
After spending two years out of baseball, he rejoined the Cardinals in 1965 — now led by GM Bob Howsam — as manager of their Class double A Tulsa Oilers and Arkansas Travelers affiliates. In 1969, Howsam, by now running the Cincinnati Reds, hired Rapp as manager of the triple A Indianapolis Indians, and in seven years Rapp won two American Association pennants there. He returned to Denver and continued his success in 1976 as manager of the Bears (by then a farm team of the Montreal Expos), winning both the regular season Association pennant and playoff championship.
St. Louis Cardinals
His success in Denver led to his hiring as Cardinals’ manager for 1977. Rapp took over after the twelve-year reign of Red Schoendienst, a longtime favorite as a Redbird player and pilot. While the 1977 Cardinals improved by eleven games and placed third in the National League East, Rapp’s disciplinarian, minor league style of managing made him very unpopular with his players, particularly Al Hrabosky. Hrabosky was ordered to shave his trademark “Fu Manchu” mustache, which was part of the carefully cultivated “Mad Hungarian” persona that he felt helped make him an effective closer. Hrabosky later said that being beardless made him feel “like a soldier going to war without his rifle”, and demanded a trade following one season without facial hair courtesy of Rapp’s rule against it.
When the Cards suffered through a seven-game losing streak that saw their record fall to 5–11 early in the 1978 season, Rapp was fired April 25 following a win at Olympic Stadium against the Expos.
Coach Jack Krol succeeded him for two games, but another former Cardinal star, Ken Boyer, was ticketed for the permanent job.