After college, he coached high school basketball teams at Beloit, Wisconsin and Stevens Point, Wisconsin that advanced to the state competition. Erickson was drafted in 1953, serving for two years in the United States Army. He began coaching college basketball at Lake Forest College, compiling 34 wins and 38 losses for three seasons between 1955 and 1958. He served as an assistant coach for the University of Wisconsin–Madison for the 1958-59 season. The following year, he succeeded Bud Foster as head coach, and compiled a 100-114 record in nine seasons. His 1962 team finished second in the Big Ten Conference--one of only two winning records the team would tally in Big Ten play from 1954 to 1995. He remained at Wisconsin until he was hired as the general manager of the Milwaukee Bucks expansion team in 1968.
After Erickson resigned as the general manager, he won the Republican Party primary, but lost in his 1970 run for the United States Senate against incumbent William Proxmire.
After the loss, Erickson became president of the Fellowship of Christian Athletes, a position that he held for 15 years. The Big Eight Conference hired Erickson to be their Director of Basketball in 1988, a position that he held until he was promoted to be the Assistant Commissioner.