By Miguel Rivera

Abner Mares is not sure why Leo Santa Cruz was unable to go forward with a planned fall rematch.

Instead, the two boxers will be involved in a FOX televised doubleheader from the StubHub Center in Carson, California.

Santa Cruz will defend his WBA "super" featherweight titles against Chris Avalos, while Mares defends his WBA "regular" championship against once-beaten Andres Gutierrez.

Santa Cruz won a close twelve round decision over Mares in 2015 in a Fight of the Year candidate.

To eliminate their number of world titles, the sanctioning body ordered Santa Cruz and Mares to fight reach other. Should they win their upcoming fights, the rematch would take place in the first half of 2018.

Santa Cruz (33-1-1, 18 KOs) and his handlers told adviser Al Haymon that more time was needed to prepare for a rematch with Mares (30-2-1, 15 KOs), who is not taking Gutierrez (35-1-1, 25 KOs) lightly.

"The truth is that I'm content to have the security and certainty that we have date, a location and a venue. Andres is strong. I do not believe in that practice of having tune-up fights. For me it's a complicated fight because someone comes in with someone with desire, hunger, and he's coming in with only a single loss to Cristian Mijares, a fighter of experience.. a fight where he lost and a lot of people say that he won," Mares told ESPN Deportes.

"I was ready [for Santa Cruz], I do not know why he wasn't ready for me. He says has wasn't, but I was. I have been talking about that fight for some time. But we know that his dad didn't want it, he wanted a preparation fight and that brought us here. I want to unify, I want to rematch with Leo, either him or Frampton, whatever they offer me."