Pac fears that he would be charged with 1st degree murder after he would literally kill Guzman in the ring.
There are lots of things that Pac would be afraid of guzman: 1. Pac might just be wasting his time training and then have the fight called of. 2. Guzamn might come in overweight and still refuse to fight. 3. Guzman might be immediately past his prime after the fight, and Pac do get blamed a lot for it. 4.Amsterdam might finally hang himself.
Pac is such a nice guy to care about Amsterdam, even if Amsterdam only cares about all the attention he can get and the widely known fact that darkness of skin is directly proportional to the quality of the fighter. [/Sarcasm]
After tonight Pacman is not shivering to say the least Guzman would actually make a great sparring partner for Pacquiao in preparation for Mayweather