The (American Football) Giants actually had a kicker finish the game with a broken neck, off course he was originally a soccer player so that might not count. 
Soccer and Football are very different sports. As you said Football is like Rugby, Soccer I would say is closer to Hockey and of course Baseball and Cricket have some similarities in skill requirements. I think Basketball’s lack of a parallel sport might be part of the reason it is now penetrating Europe so well. It may well grow into the #2 world team sport if it is not there already.
The only real reason soccer is dismissed in the USA is that it still remains a kids game (in the USA) that people grow out if here. It is not our sport and in general we just don’t care about it.
Football holds a special place as it is an Event Sport and the big gambling sport at the same time. Baseball holds its own as it is the American Pastime and has all that tradition and history and legends and stats. Hockey has been slipping for decades and most seem to consider it Canada’s sport. Basketball is solid but except for Jordon just never could compete with the big two team sports in the USA.
The one comment that always drives me crazy from European or Aussies though, is the whole “American football players are wusses because they wear pads” meme. First of all, one of the major things allowed by wearing pads is letting players use their body as weapons with near reckless abandon. This produces collisions that are more violent than I’ve seen in any other sport. Second, I don’t want to minimize the contact in other sports, but in American football the contact is more pervasive. Just about every player on the field (minus those wussy corners) are hitting somebody as hard as they can on every single play. The only sport I know that comes close is Rugby, and having played both fairly extensively, I can say its not really that close.