Cesar Gracie, the trainer and manager for Nick Diaz, is pushing hard for BJ Penn to accept a five-round fight at UFC 137 in the show’s freshly named main event.

Yesterday it was learned UFC welterweight champ Georges St-Pierre was forced to pull out of a planned fight with Carlos Condit due to a knee injury, and the co-main event of Diaz-Penn was elevated to the main event position.

The UFC has said they would not force fighters to accept the new five-round main event decision if they take the fight on short notice. That hasn’t stopped Gracie from trying to goad “The Prodigy” into getting the bout changed.

“These guys have to prove they are ready. These guys are fighters. BJ has always said he’s a warrior,” said Gracie, in an interview with MMAFighting. “The old school days of MMA, back when it was NHB (no holds barred), they fought forever. If they can’t go five rounds against each other, how are they going to fight five rounds against GSP?”

Gracie said Dana White is fine with the change if Penn agrees though the UFC President has neither confirmed or denied that statement. Gracie also added that Diaz was quick to agree to five rounds once he heard it would be the main event for the pay-per-view show.

“Don’t be scared, homie. Let’s make it five rounds,” Gracie slyly added in homage to Diaz’s often quoted line.

This has been a long and strange ride for UFC 137, as the original main event featured GSP-Diaz. Diaz, however, failed to show for several press conferences and was removed from the fight and replaced by Condit. The UFC eventually decided to place Diaz in a bout with Penn, and now the former Strikeforce welterweight champ is back in the spotlight.

MMATraining Take: Yes, Diaz-Penn for five rounds would be great, but the odds of this fight needing to go the distance isn’t very good anyway. Diaz is stepping up big-time in terms of competition, while Penn is used to this kind of pressure. Expect this one to end before the bell rings in the third round regardless of if it’s a three or five round war.