Casa should take this if he's still got enough left in the tank. He's just a better fighter than Diaz, plain and simple. I see Diaz getting stopped with a left hook late on. Casa's chin has always been decent, Diaz doesn't have the power to stop Casa or the ability to bring anything to the fight that Casa hasn't already seen before.
I agree, Diaz won't stop him with any one punch in his arsenal - and a corner/ref stoppage would require Casamayor to be taking continuous punishment. Even stunned, even old, even with shot reflexes, even withstanding Diaz' pressure and output, I simply do not see Joel standing still and absorbing punishment for more than a few seconds at a time. Casamayor by late stoppage would be my inclination - letting it go to the cards could be dangerous as not every panel of judges is going to reward his effective but intermittent countering ability in the face of Juan's workrate. My "decision" pick in the poll was because I think he would do the better work, and he would likely win on my scorecard. But I could easily see him getting robbed if he leaves it in the hands of others.
I'd love to see it, but somehow I doubt we see Diaz in with a boxer anytime soon. And on top of that, I don't think I'm way off thinking Casa has more pop at 135 than Paulie does at 140. Then on the other hand, of Diaz's options right now, Casa might be the safest one. I'm really curious who they put Diaz in with next.
I do think there are big question marks over the current state of Casa though. Physcially he's another year down the line, and his legs have already gone. Mentally he's not always shown a dedication to training, even in his prime, so its not totally unlikely that he comes in out of shape and as a shadow of his former self, and Diaz just outworks him to a UD. Casa is a lot easier to hit these days. That's kind of my 'worst case scenario' though.
This version who lost to a Santa Curz, who almost lost to Katsidis and who gave JMM some problems, who is also in decline but got KO'd. Yeah...this version Diaz wins on points by out working and smothering Casa in a clear victory.
The JASC fight was an old man on an off night underestimating an extremely game challenger. He did not almost lose to Katsidis. :nono