VAN NUYS, Calif. – Former world champion Julio Cesar Chavez Jr. held a media workout on Friday in front of a packed house at Ten Goose Boxing Gym in Van Nuys, Calif., as the Mexican superstar prepares to make his SHOWTIME CHAMPIONSHIP BOXING® debut on Saturday, April 18, at the StubHub Center in Carson, Calif., live on SHOWTIME (10 p.m. ET/7 p.m. PT).

In the main event of the SHOWTIME CHAMPIONSHIP BOXING doubleheader, Mexican superstar Chavez, Jr. (48-1-1, 32 KOs) meets dangerous brawler Andrzej Fonfara (26-3, 15 KOs) in a 12-round light heavyweight bout.

In the 10-round co-feature, top 10 ranked junior welterweight contender Amir Imam (16-0, 14 KOs) will aim to move one step closer to a world title opportunity when he makes his second start of 2015 against fellow power-puncher Walter Castillo (25-2, 18 KOs).

Julio Cesar Chavez, arguably the greatest Mexican fighter of all time, made an appearance during his son’s workout to show his support and offer words of encouragement.

“I am very focused going into this fight. I have changed a lot mentally this past year. I am fighting [Andrzej] Fonfara now because I like big opponents. I like the challenge of fighting good, hungry fighters. Just because Fonfara doesn’t have the name recognition of other fighters, it doesn’t make him an easy fighter. He’s tough," Chavez said.

“I feel comfortable at light heavyweight. Any time that you can add a couple pounds, you feel better. Although I will be fighting at 175, I feel most comfortable at 168 as a boxer. Since I have had one year off, it was a better choice to fight at this weight so that I could see how my body feels.

“Since I have added a few pounds, I have become a more physical and stronger boxer. The light heavyweight division has very big and physical contenders.

“Joe [Goossen] is a great trainer. He is a great motivator to his fighters and makes them better. I have worked very hard with him for the 35 days we spent together in Lake Tahoe.

“When I was training with Freddie Roach, it was very different. I think Freddie is a great trainer, but Joe also has a lot of experience and we have made a connection together.

“I really liked training in Lake Tahoe. The altitude, the ring, everything I needed was there. I felt very comfortable up there and I would like to come back there to train for a fight again.

“I promise a great fight, this is a very exciting fight. Fonfara isn’t an easy opponent, but he has never seen an opponent like me.”