Semproch was signed by the Phillies as an amateur free agent in 1951, but he did not make his big league debut until many years later – on April 15, 1958, against the Cincinnati Reds.

[1] In his first major league game, he gave up a hit and a walk, struck out two, and earned the win in a three inning relief appearance.

He was traded to the Tigers on December 5, 1959 with Chico Fernandez for Ken Walters, Ted Lepcio, and minor leaguer Alex Cosmidis.

Despite that moderate success, he was traded on June 15, 1960 to the Los Angeles Dodgers with cash for Clem Labine.

Following his big league career, he worked as a bar manager at his brother's Italian restaurant.