Widenhofer is best known for helping the Pittsburgh Steelers "Steel Curtain" defense that won four Super Bowls in the 1970s. He later served unsuccessful tenures as head coach at Missouri and Vanderbilt University. Widenhofer attended Riverview High School in Riverview, Michigan and played linebacker at Mizzou from 1961–1964 under coach Dan Devine. He went on to receive a master's degree at Michigan State University.