I watched the David Haye vs. Wladamir Klitchko fight this past weekend. I thought Kiltchko tried to make a good fight out of it, but Haye ran for 12 rounds. At the end of the bout he said he couldn't push off is right foot (his power side) and this his "Haye'-maker (but he could run for 12 rounds). I'm of of the believe that if you are really injured or hurt you won't fight. Athletes are always injured. I know of fighters to fight with busted ribs, broken noses, etc. In an earlier blog, I put a video of me fighting with a torn ACL in a tournament. So, it's not like one bout and you just fight off of the adrenaline. You get to go cool down some, wait on your next fight, start swelling in a cold room and go back out for another match. Here's another video 2 years later of me having problems with the same injury (I have torn both knees in the ring in fights). Now I was definitely fighting for far less than what Haye fought for in last Saturday's Heavyweight title bout.
Here is a clip for the final match of The 2004 Shidokan Welterweight World Open agains the tough "Hollywood" Dave Huelett. I turn of the pain receptors until the end of the match. As you will see I still throw some kicks with it. Round kicks are OK, but straight kicks, nope. I basically limp around during the match.