Johnson was born Keshon Lorenzo Johnson on July 17, 1970 in Fresno, California.
Johnson was drafted by the Chicago Bears in the seventh round of the 1993 NFL Draft. He spent his first season with the team before splitting the 1994 NFL season with the Bears and the Green Bay Packers. Johnson began the 1995 NFL season with the Detroit Lions, but did not see any playing time with the team and later re-joined the Bears.
He played at the collegiate level at the University of Arizona.