For several years, the theory was that junior middleweight champion Saul (Canelo) Alvarez would not move from 154 to 160 to fight multiple middleweight champion Gennady Golovkin because “GGG” was too big for him. But that excuse is out the window now because Golovkin suddenly is viewed as a “small middleweight,” and Canelo is scheduled to meet Julio Cesar Chavez Jr., who has been fighting as a light heavyweight, at a 164.5-pound catchweight in May.

Golovkin weighed in Friday at 159.6 pounds compared to 159.8 for WBA middleweight champion Daniel Jacobs before their unification bout scheduled for Saturday night at Madison Square Garden.

Representatives of both camps said they expect Jacobs to come to the ring at about 175 pounds, which is what he weighed 30 days before the bout, after he hydrates. Golovkin, who was at 165 pounds 30 days before the fight, is likely to be in the 165-70 range.

“Gennady is a small middleweight,” said Abel Sanchez, who trains Golovkin. “I think we’re beginning to see that with all the seven-days and the 30-day weigh-ins. We’re seeing he is a smaller middleweight compared to the guys he’s fighting.”

Sanchez said Golovkin (36-0, 33 KOs) always has adapted to bigger opponents, and his string of 23 straight knockouts is proof of that. But Jacobs (32-1, 29 KOs) has demonstrated power throughout his career, and he enjoys the notion of being the bigger man.

“I’m the bigger guy, but boxing is a tricky game,” Jacobs said. “Sometimes, that might not make a difference. But I do believe it will be a big difference in this fight. My size and my speed and my IQ will all add up and make me victorious.”

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Another factor that will be interesting to track is crowd support. Jacobs is from Brooklyn, where he has a relationship with Barclays Center, but he has fought previously at the Garden as a pro and as an amateur. Golovkin is from Kazakhstan and is based in California, but this will be his fifth appearance at the Garden, which has become his East Coast home.

“Yes, it’s very interesting,” Golovkin said of the anticipated sellout in the main arena for the HBO pay-per-view event. “Daniel represents Brooklyn. I represent Manhattan. It’s little different. Madison is my place. For Daniel, I think it’s Barclays. Right now, it’s more interest, not like last time with David Lemieux because he is from Canada. Daniel is from Brooklyn.”

Jacobs’ history at the Garden is the source of positive inspiration. “I won my four Golden Glove championships here,” Jacobs said. “This will always be my home, too. I’m a Barclays representative, but at the end of the day, I’m a New York guy. This is my state, this is my city, and I look forward to keeping that title.”