Rios was supposed to fight Mauricio Herrera in a junior welterweight bout July 7 on HBO at Home Depot Center in Carson , Calif. .
Rios withdrew because of a nagging right elbow problem .
Rios was supposed to fight Mauricio Herrera in a junior welterweight bout July 7 on HBO at Home Depot Center in Carson , Calif. , but he withdrew because of a nagging right elbow problem .