Cesar Gracie, head trainer of the enigmatic Nick Diaz, was a recent guest on HDNet's "Inside MMA," breaking down his fighter's upcoming clash with B.J. Penn in the UFC 137 main event.

Gracie goes into deep detail about Diaz's respect for the "Prodigy," even mentioning that he hopes it doesn't have an impact on the outcome of the 170-pound bout because the Stockton, Calif.,-bred brawler typically performs best against enemies (See Frank Shamrock).

The video ends with Gracie saying that Diaz and Penn will likely put all their happy history behind them for 15 minutes and go after each other on the ground, as well as on their feet, as if they were sworn enemies.

Anyone else concerned? Or, will their similar styles and "fighter mentalities" translate into an action-packed, instant classic?