By Keith Idec

NEW YORK — Julio Cesar Chavez Jr. has heard Sergio Martinez dismiss Chavez’s size advantage more times than the WBC middleweight title-holder could count during their four-city press tour over the past week.

Once they’re finally in the ring together on Sept. 15, however, Chavez expects Martinez to have a lot of difficulty dealing with the unbeaten Mexican’s two-inch height and probable 15-pound weight advantages at UNLV’s Thomas & Mack Center.

“He’s never fought a bigger guy than me,” the 6-foot Chavez said of Martinez, who did defeat heavy-handed, 6-foot-2 Kelly Pavlik in their April 2010 middleweight championship match in Atlantic City. “Without a doubt, I’m the strongest guy he’s ever going to face. And I think it’ll show in the ring, that I’m a stronger guy. He’ll be surprised with how big and strong I am.”

The 26-year-old Chavez won’t be the least bit surprised if his size and strength make Martinez retreat all night.

“I think he’s going to be moving in the ring more than ever,” Chavez said. “He knows he can’t beat me if he stands to fight me. But as long as there are some ropes around the ring, he’s not going anywhere.”

Martinez (49-2-2, 28 KOs) has won his last four fights either by knockout or technical knockout, but Chavez (46-0-1, 32 KOs) has shown a granite chin throughout his transformation from protected prospect into a championship-caliber prizefighter. The son of Mexico’s most famous fighter walked through everything thrown by Andy Lee (28-2, 20 KOs) and Marco Antonio Rubio (54-6-1, 47 KOs), both respectable punchers, in his last two fights and doesn’t think the 5-foot-10 Martinez will be able to back him up.

Martinez suspects he won’t have as many chances to check Chavez’s chin as he would have had if they would’ve fought a year or two ago, when Chavez’s defensive deficiencies were much more exploitable.

“He really has progressed a lot, in a really intelligent way,” Martinez said. “Now he tries to take advantage of the whole ring, not like before. That is very important for him because before he used to receive a lot of punishment that now he tries to avoid.”

Chavez, meanwhile, contends he hasn’t seen much improvement from Martinez, a late-blooming, 37-year-old who’s widely recognized as one of the top three pound-for-pound boxers in the world.

“There are some things in any fighter,” Chavez said. “You’ll see he always makes the same mistakes. And no matter how long they fight, they never change. There are some in there that Martinez makes. There’s some in there that you can see. It’s impossible for a fighter to change, so we have to take advantage of those mistakes. He keeps making them in every fight I see.”

Keith Idec covers boxing for The Record and Herald News, of Woodland Park, N.J., and BoxingScene.com.

Tags: Julio Cesar Chavez Jr , Sergio Martinez , Chavez-Martinez , Chavez vs Martinez