If you are or were just watching the Preseason Week 2 game against the Steelers, then you probably saw the horror of watching Jordy Nelson make a 1st quarter catch only to immediately hit the deck with an injury. The fact that Nelson was untouched on the play only made it more likely that the condition was serious.
As just mentioned in the article of what to watch for in this game, even though there might be some storylines making preseason games close to watchable, the actual bottom line is that you want to get through these games without suffering any major injuries.