Hirsch served in the United States Marine Corps from 1944 to 1946 and then played professional football in the All-America Football Conference (AAFC) for the Chicago Rockets from 1946 to 1948 and in the NFL for the Los Angeles Rams from 1949 to 1957. During the 1951 season, Hirsch helped lead the Rams to the NFL championship and tied or broke multiple NFL records with 1,495 receiving yards, an average of 124.6 receiving yards per game (still the third highest season average in NFL history), and 17 touchdown receptions.