If a group of people planned ahead of time to try to injure another person and succeeded in doing so and/or think they succeeded in injuring him, were their actions criminal? I would think people planning and then attempting to injure another person is criminal. What if they're playing football? In the NFL? Should that matter? Not to get too legalese-ee regarding this topic but, look up mens rea.
Reports are that New York football Giants players may have intended to injure San Francisco 49'er returner Kyle Williams. Giants players appear to admit that they knew he had a history of concussions and tried to knock him out of the game or concuss him. In other words, with malice aforethought, they tried to and succeeded in injuring him, or at the very least they think they did. One Giants player even brags that after one early hit on Williams, the San Fran returner looked "dazed." Plus, if coaches encouraged and/or instructed Giants players to try to purposefully injure San Fran's Williams, would that not constitute a conspiracy to injure another person?
In other words, besides being beyond dirty players/coaches for all but admitting they were trying to injure a fellow NFL player, is what the NY Giants players did (try to/actually injure Williams) criminal? Of course now, maybe realizing how damning their quotes were after the game, those same Giants now deny they were trying to injure Williams. But, speaking of the Giants' quotes, take a look at them.
Hockey players have been charged with crimes for their on ice, intentional acts that resulted in injury to another player. Why should NFL players' actions not be examined in the same manner? Did Giants players intend to injure another player? If the answer is "yes," why should they not have to answer for their intentional, and potentially criminal actions?