By Keith Idec

LAS VEGAS – Just a few hours after Jorge Lara made his grand arrival at MGM Grand on Tuesday, the featherweight contender exited his fight against Joseph Diaz Jr.

ESPN.com reported Tuesday night that Lara suffered a back injury at a Las Vegas gym Tuesday and withdrew from his scheduled 12-round bout with Diaz on the Canelo Alvarez-Gennady Golovkin undercard. Mexico’s Rafael Rivera quickly accepted an opportunity to replace Lara on four days’ notice, so Diaz’s fight will remain on the HBO Pay-Per-View undercard Saturday night at T-Mobile Arena.

It hadn’t been determined by Tuesday night, though, if the WBC will sanction Diaz-Rivera as an elimination match that would move the winner closer to a shot at its featherweight champion, Gary Russell Jr. (28-1, 17 KOs).

The 24-year-old Diaz (24-0, 13 KOs), a 2012 American Olympian from Downey, California, is ranked No. 2 among the WBC’s 126-pound contenders. Lara (29-0-2, 21 KOs), of Guadalajara, Mexico, is ranked fourth by the WBC.

Mexico’s Rivera (25-0-2, 16 KOs) was not ranked among the 40 featherweight contenders the WBC listed on its website as of Tuesday night. Rivera had been training for a fight against the Philippines’ Drian Francisco (29-4-1, 22 KOs) on September 22 in Ontario, California.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.