Greenwood was a member of the famed Steel Curtain defense of the 1970s that won four Super Bowls in 1975, 1976, 1979 and 1980. Greenwood was famous for wearing gold-colored shoes. The story was that he wore them to help the public address announcer identify him when making tackles.
During his career, which spanned from 1969-81, Greenwood amassed 73.5 sacks, ranking him second on the franchise list behind Jason Gildon. Unlike teammate Joe Greene, Greenwood was never inducted into the Pro Football Hall of Fame. This is something that does not sit well with Art Rooney Jr.:
"The saddest thing is, he never got into the Hall of Fame," Mr. Rooney said. "To me, it's terribly sad. He deserves to be there."
In 2005 and 2006, Greenwood made the Hall of Fame finalist list but was never able to earn a bust in Canton. Throughout his career, Greenwood was named to a pair of All-Pro teams and five Pro Bowls.