By Dan Ambrose: WBC middleweight champion Julio Cesar Chavez Jr. (46-0-1, 32 KO’s) is seen by many boxing fans as someone that can’t be knocked out no matter how hard he’s hit on the button. We’ll see whether that’s in fact true or not when he defends his title against 37-year-old southpaw Sergio Martinez (49-2-2, 15 KO’s) next month on September 15th in Las Vegas, Nevada.

Chavez Jr. has done a good job lately in walking through the shower of power shots thrown at him by the likes of Andy Lee, Marco Antonio Rubio, Peter Manfredo Jr, and Sebastian Zbik without getting seriously hurt. However, Zbik seemed to stun Chavez Jr. a few times, and Chavez Jr. looked uncomfortable with the shots that Lee was raining down on him until he was taken out. Chavez Jr. was also staggered by John Duddy, a fighter with only average power.

Against Martinez, Chavez Jr is going to be getting hit much harder than he ever had before and it’s going to be coming with a lot more speed and from the southpaw stance. Chavez Jr. obviously is sparring with a lot of southpaws to get read for this fight, but not one like Martinez.

Chavez Jr’s size seems to help him absorb a lot of shots, because being able to walk into a ring a cruiserweight sized fighter has to help his ability to take big shots from middleweight sized guys. The shots don’t move him like they would a fighter weighing in the 160s. However, Martinez hits like a truck and it doesn’t matter how good Chavez Jr’s chin is, he’s only human and can only stand so much power per square inch before he gets knocked cold.

He was able to take Rubio’s best shots, but Rubio lacked hand speed and is more of a junior middleweight than a middleweight. The lack of hand speed seemed to be Rubio’s main problem.

Chavez Jr does get hurt, but he recovers quickly and most of his opponents have been guys that only thew one punch at a time. If Martinez can hurt Chavez Jr., he may look to capitalize on that by unloading on him with a flurry of shots before Chavez Jr. can recover.