Gilberto Ramirez switches trainers as he moves to light heavyweight

Super middleweight world titleholder Gilberto "Zurdo" Ramirez, who is moving up to the light heavyweight division, announced on Monday that he will head into his new weight class with a new trainer in Julian Chua.

Ramirez, of Mexico, not only has parted ways with Hector Zapari, who had trained him since he was 12 and throughout his entire 10-year professional career, but he also split with manager Jesus Zapari, Hector's father. Ramirez will now be self-managed.

Ramirez gave no reason for the split, but according to sources close to the fighter, there were financial issues between him and the Zaparis that led to the breakup.

Chua is not a well-known trainer, but he has worked with some pros in recent years in Southern California, where he will also prepare Ramirez for his 175-pound debut, which promoter Top Rank officially announced on Monday.

Ramirez will face an opponent to be determined in a 10-round fight on April 12 at the Staples Center in Los Angeles in the co-feature of the Top Rank Boxing on ESPN+ card (11 p.m. ET). The main event was also made official on Monday: pound-for-pound king and unified lightweight world champion Vasiliy Lomachenko's mandatory defense against former world titlist Anthony Crolla. That fight was agreed to last week, but now it's signed, sealed and delivered.

Ramirez (39-0, 25 KOs), 27, a southpaw, has defended his super middleweight title five times but has struggled to make the 168-pound division limit and is giving 175 pounds a try. Ramirez has left open the possibility of returning to super middleweight after his April 12 bout, though it is unlikely.

"I am very motivated because of all the new things I have been doing to advance my career," Ramirez said. "I am very excited to fight at Staples Center for the first time, as I consider Los Angeles my second home. I know there will be many Latino fans supporting me. I want to become an idol of Mexican boxing, and nothing will stop me as I work to fulfill my dreams. I am also working with a new trainer, Julian Chua, who is pushing me to become the best fighter possible."

With a win at light heavyweight, Ramirez will put himself in the mix for major fights, especially because Top Rank also promotes world champion Oleksandr Gvozdyk, world titlist Artur Beterbiev and is the co-promoter for world titlist Sergey Kovalev and former titleholder Eleider "Storm" Alvarez.

Ramirez still holds his 168-pound title even though last week the WBO listed it as being vacant on its website. That was an error, and Ramirez was restored the following day.

Lomachenko last fought in Los Angeles in August 2017 when he stopped Miguel Marriaga in the seventh round in defense of his junior lightweight world title at the Microsoft Theater, which is across the street from Staples Center. Now Lomachenko, whose drawing power has been on the rise, is moving on to fight in the big arena.

"Staples Center is the perfect venue to showcase one of boxing's great fighters, Vasiliy Lomachenko, who will test himself against a top contender in Anthony Crolla of Great Britain," Top Rank chairman Bob Arum said in announcing the fight.

Lomachenko (12-1, 9 KOs), 31, who has won world titles in three weight classes, will make the second defense of his lightweight crown. He won a 135-pound title by 10th-round knockout of Jorge Linares -- who owns two decision wins over Crolla in world title bouts -- in May and then unified two belts in his next fight with a one-sided decision over Jose Pedraza in December. Lomachenko, a southpaw and two-time Olympic gold medalist from Ukraine, is happy to be returning to fight in Los Angeles.

"Los Angeles boxing fans are passionate and knowledgeable, and I look forward to putting on a spectacular show for them at Staples Center," he said. "Crolla is my mandatory challenger, and I like that he always comes to fight. He's going to make the most of this opportunity."

Crolla (34-6-3, 13 KOs), 32, who earned the mandatory position with a unanimous decision over Daud Yordan on Nov. 10 in Manchester, England, Crolla's hometown, will be fighting in the United States for the first time and outside of the United Kingdom for only the second time. He's up for the challenge.

"I cannot wait for this. These are the fights you are in the sport for," Crolla said. "People will say that I have got nothing to lose, but I am genuinely going over to L.A. to shock the world. I will concentrate on me. Firstly, I have to make sure the best Anthony Crolla turns up that night. I'm not worried about that.

"Preparing for Lomachenko is hard because he's so unorthodox. He's that good that when he does something wrong, he gets away with it. You wouldn't teach some of the things that he does. He's so unique in that respect."