Prior to the NFL, Testerman was on Clemson's football team.[1]
Testerman was drafted by the Miami Dolphins in the tenth round of the 1976 draft.[2] In August 1976, the Dolphins traded Testerman to the Philadelphia Eagles for a future draft pick.[1] He was then traded to the Seahawks in early September.[3] Testerman made his NFL starter debut against the Dallas Cowboys on October 3, 1976.[4]
Testerman sat out the 1979 season due to an injury. He joined the Miami Dolphins for the 1980 season.[5]
After retiring from the NFL, Testerman was involved in various coaching and non-profit capacities. He periodically substituted for Albemarle High School.
In 2018, Testerman died from the effects of dementia at the age of 65.[6]