Rolando Reyes will replace Joel Casamayor as Julio Diaz’s opponent on the April 4 “Lightweight Lightning” pay-per-view card in Austin, Texas, according to Golden Boy Promotions matchmaker Eric Gomez.

Golden Boy considered scraping the fight but Diaz, who has been in training, was willing to fight anyone.

Reyes (30-4-2, 19 knockouts) was a late replacement when he lost a one-sided decision to Jose Luis Castillo in February 2006. The fringe contender from Oxnard, Calif., has fought only four times since then, winning each fight.

Diaz (36-4, 26 KOs) is 2-0 since he was stopped by Juan Diaz in October 2007. He is THE RING’s No. 4-rated lightweight.

Casamayor, a former titleholder, pulled out because of a lower back injury.

Edwin Valero (24-0, 24 KOs) and Antonio Pitalua (46-3, 40 KOs) fight for the vacant WBC title on the lightweight card. Also, Michael Katsidis (24-2, 20 KOs) faces Jesus Chavez (44-4, 30 KOs), and Carlos Hernandez (43-7-1, 24 KOs) fights Vicente Escobedo (19-1, 12 KOs).