I don't get that. Someone who is a good guy, gets aplause when he gets injured. In cases like Terrel Owens, or Warren Sapp, or Randy Moss (a couple years ago I mean, lately he has shown a newfound, and respectable maturity), you can almost understand it (being they all have/had such abrasive personalities). Not that I condone it (these are people after all, and their very livelyhood and bodies are on the line, remember Dennis Byrd?), but it is almost understandable.
Even at home on my couch I applaud when an injured player waves "I'm OK" at the crowd.