Name: Mark Gastineau
Birth Name: Marcus Dell Gastineau
Birthplace: Ardmore, Oklahoma, USA
Hometown: Scottsdale, Arizona, USA
Height: 6′ 5½″ / 197cm
Reach: 77″ / 196cm
Boxing Record: click
He recorded 22 quarterback sacks in 1984, which established an NFL record that would stand for 17 years.
Gastineau was leading the AFC in sacks through the first seven weeks of the 1988 season when he surprislingly announced his retirement. He said he wanted to spend more time with his fiance, whom he feared had uterine cancer. It proved to be a false alarm. Years later, Gastineau admitted another reason he quit was because he was concerned he would fail another drug test and the public would learn he used steroids. 
Gastineau took up boxing and turned professional in 1991. He won his first nine fights by knockout, but there were allegations that some of his fights were fixed by his promoter, Rick "Elvis" Parker.
Parker was reportedly promised a big payday against George Foreman if he could get Gastineau to 12-0.
They had a rematch in December 1992, and Gastineau won by a sixth-round knockout. After the fight, Anderson insisted that he was drugged by Parker. He said he was light-headed, nauseous and hallucinating during the bout. A year and a half later, Anderson shot Parker dead.