Between 1982 and 1985, Spencer was an All-American running back for the University of Oklahoma. In addition, he was selected 133rd overall in the 5th round of the 1987 NFL Draft by the Houston Oilers. Tillman also spent two seasons with the Edmonton Oilers (1987-1988). He later joined the San Francisco 49ers, where he spent three seasons (1989-1991).
During the seven-month off-season in 1987, he began his broadcasting career as an anchor and reporter at KPRC-TV. Tillman joined CBS Sports in 1999 as a main studio analyst for “College Football Today,” where he worked for 16 years. Apart from that, Tillman worked as a correspondent for the Network’s NCAA tournament coverage for four years. Tillman most recently joined Fox Sports News in 2015, reuniting with Tim Brando on Fox CFB.