Callum Smith admits that he just wasn’t good enough to beat Canelo Alvarez on December 19.

The former WBA super middleweight champion won’t blame problems making weight, a truncated training camp or anything other than that indisputable fact for his lopsided loss to Alvarez in their 12-round, 168-pound title fight nine months ago at Alamodome in San Antonio. Liverpool’s Smith simply is looking forward to fighting for the first time at the light heavyweight limit of 175 pounds when he encounters Lenin Castillo in a 10-rounder Saturday night in London.

The 6-feet-3 Smith feels fresher after not having to drop seven additional pounds as this training camp wound down for an appearance on the Anthony Joshua-Oleksandr Usyk undercard at Tottenham Hotspur Stadium. Smith (27-1, 19 KOs) is confident his extra energy will reflect in his performance against Castillo (21-3-1, 16 KOs), a career-long light heavyweight who possesses power.

The 31-year-old Smith probably would’ve moved up to light heavyweight even if he had upset Alvarez in what would’ve been a career-changing victory.

“Again, it’s hard to speak about it without looking like I’m blaming the weight for the loss, and I’m not,” Smith told IFL TV during an interview that was posted to its YouTube channel Thursday. “Look, the better man beat me on the night. He was too good for me on the night, and there’s no excuses. But I knew me time for the bit was coming towards the end at 168. And even if I’d have won the fight, I think as a fighter, you know, and I was still doing the weight comfortable, you’d always wanna be a two-weight world champion.

“There’s always goals you wanna set yourself and mine was to unify or step up in time and be a two-weight world champion. But I think it comes to a point where it wasn’t in my hands. I had to move up for me own performances’ sake. Me performances were starting to dip. And I’m excited about it. I feel good. I feel better. And hopefully we’ll see some improvements in me fight, and we’ll see a better version of me.”

Caesars Sportsbook lists Smith as a 40-1 favorite to beat Castillo, who has lost unanimous decisions to WBA light heavyweight champ Dmitry Bivol (18-0, 11 KOs) and former WBA interim light heavyweight champ Marcus Browne (24-1, 16 KOs).

The Smith-Castillo contest will be part of a Sky Sports Box Office pay-per-view show in the United Kingdom and Ireland (6 p.m. BST; £24.95). DAZN will stream their bout as part of the Joshua-Usyk undercard in the United States (1 p.m. EDT) and more than 170 additional countries and territories.

Keith Idec is a senior writer/columnist for krikya360.com. He can be reached on Twitter @Idecboxing.