Team: New York Mets
Watch It Here
This one was hard to watch because you could see it all happening. Beltran (the center fielder) and Cameron (the right fielder) managed to time their dives at just the right moment so that they smashed their faces together, knocking each other out cold. Both suffered concussions and missed significant time, but Cameron took the worst of it; he also broke his nose and cheekbone, and was removed from the field on a stretcher. Both have recovered well since this incident, with Beltran still playing productively and Cameron retiring just prior to the 2012 season.