Reinfeldt played as a safety for eight seasons in the NFL with the Oakland Raiders in 1976 and with the Houston Oilers from 1976 to 1983.

An All-Pro safety with the team from 1976 to 1983 in Houston, he re-joined the franchise after spending seven years with the Seattle Seahawks.

In Seattle, Reinfeldt last held the title of vice president of football administration and was responsible for player contract negotiations, salary cap management, player evaluations and numerous aspects of the day-to-day football operations.

In eight seasons at Green Bay, he served a number of roles, including chief financial officer for three years (1991–1993) and VP of administration from 1994 to 1998.

Before joining the Packers’ front office in 1991, Reinfeldt spent three years (1988–1990) at the University of Southern California as the associate athletic director and spent another three years (1985–1988) with the Los Angeles Raiders as the chief financial officer.