If you dont think football (sorry soccer) is Dangerous then you have not seen the Leeds or Wimbledon of the 1980's play. Or as a fan you never went to Millwall, West Ham, Chelsea, Carlisle, Man City in the 1980's. These small clubs got terrible names for the firms (gangs) that followed them. As a kid I went watching BWFC (Bolton Wanderers) away to Man City. The streets around the ground were terraced with back alleys between the backs of houses. We walked past one and within seconds hundreds of thugs were laying into Men, Women and Children with bricks, bottles , scaffolding and more. This was after they had won !
On the pitch careers have been ruined by some truely bad tackles. Head Butts, Biteing, Ball grabing (not the game ball), punches and elbows (not the padded type but the bare knuckle type) are all in the game, you just need to know who to watch and when. The game is cleaner now but this has speeded it up quite a bit.
Just search Duncan Ferguson and Everton on youtube. Its every bit as dangerous as American Catch (sorry American football)