If you're a professional athlete, one of the worst things that someone can call you is a quitter. It's one thing to try to win and to lose. There's some level of respect in that. But quitting before you even get the chance to lose? Well, that's the biggest L you can possibly take. Bleacher Report just "celebrated" some of the biggest quitters in sports of the past 15 years over here. Can you believe these guys threw in the towel?

[via Bleacher Report]