A "meatball" was coined by sulley to describe a type of fan (ie - most fans) who have terrible opinions. They tend to love things like grit and guys who run out grounders and "play the game the right way." They get boners over the unwritten rules, hate showboating and fun and are generally, well, meatballish. Their idea of good players tend to be annoying little white guys like Theriot or Eckstein, while non-white players who dare to show any emotion are just lazy, selfish attention hogs who only care about padding their stats. Think of how the average Cubs fans rails about Sammy despite how amazing he was. THAT's a meatball. A meatball might even love Contreras now because he's the new hotness, but if he keeps up his awesome little displays of confidence and coolness, as soon as he struggles they will LOATHE him and be calling up Barry Rozner to hurl spittle about how he's the new Aramis.