[hirvi74]

I think intentions should be considered when describing something as violence in a sport.

I assume you are unfamiliar with "head hunting?" If so, it's where a team or player intentionally tries to injury the better player(s) on the opposing team in order to secure a competitive advantage.

Here are some examples of what I would consider "violence" in hockey, some of which, could be argued to be head hunting:

https://www.youtube.com/watch?v=PHPktgmbdbA