In 1969, Wilkerson got his first job on KMOX in St. Louis. He partnered with Bob Costas for the first year of St. Louis Spirits (ABA), 1975-76. He served as a radio play-by-play announcer for St. Louis Cardinals ("Big Red") football from 1973 until the team left for Phoenix following the 1987 season, and returned for one season in 1994, the franchise's first as the Arizona Cardinals.. He became the first black to be the main play-by-play man for an NFL team, and the first color announcer when he teamed up with Dan Kelly to do St. Louis Blues (NHL) games. He also broadcast Missouri Tigers football from 1976 until 1993. While handling football games, he also co-hosted KMOX's "Total Information AM" (The Morning Show) with Bob Hardy and Wendy Wiese for many years. He and Wiese changed stations in St. Louis for rival KTRS in 1996. He retired from radio in 2006.
