There isn't much darkness here, but The Dark Side of the Game is a pretty good book. Green played linebacker and defensive end for the Atlanta Falcons from 1986-1993 (the book is copyright 1996), and he has since written a couple dozen books, mostly fiction. This book is not his life story, though. Instead, it is a collection of essays about various aspects of the NFL, a mixture of recollections and opinions.
The Dark Side of the Game is a well-written and thoughtful survey of pro football circa 1995. Although a few chapters about particular players such as Deion Sanders date this book, I think most of it is still relevant today.