Unbeaten minimumweight champion Oscar Collazo has suffered a rib injury in training and will not fight for Ricardo Sandoval's two world flyweight titles in October as planned, promoters announced on Friday.
Collazo, a 29-year-old Puerto Rican southpaw who is 15-0 with 12 knockouts, was to have faced 27-year-old American fighter Sandoval on 10 October at Chicago.
Sandoval, 27-2 with 18 knockouts, was risking his World Boxing Association and World Boxing Council flyweight (112-pound/50.8kg) crowns against Collazo, the WBA and World Boxing Organisation minimumweight (105-pound/47.6 kg) world champion.
"This is a fight I wanted deeply," Collazo said. "I pushed for this matchup to happen because I wanted to face this challenge and because I know how much it means to everyone who has been waiting to see it.
"Although today we have to accept this reality, this isn't the end. My wish, and my team's, is that we can find a new date and that this fight can happen."
Golden Boy Promotions said in a statement the card would continue with American Floyd Scofield, 19-0 with 13 knockouts, facing Canadian Lucas Bahdi, 20-0 with 15 knockouts, for the vacant WBA lightweight title.