Milton, a quality first baseman, was a four-year letterman at Bradley University in Peoria, Illinois. He was selected for the South Side team in the 1939 Muny League All-Star team.

Gruber played with the Gebken-Benz team that won the 1942 city championship, then enlisted in the U.S. Army Air Corps and played military service ball in New Mexico. He went on to coach and manage Khoury League teams from 1955 to 1960.

Milton W. Gruber passed away on April 3, 2008.