By Dan Ambrose: WBC middleweight champion Julio Cesar Chavez Jr. (44-0-1, 31 KO’s) is going to be getting tested for the first time in his career against a big puncher in his fight next month against Marco Antonio Rubio (53-5-1, 46 KO’s) at the Alamodome in San Antonio, Texas.

If Chavez Jr. doesn’t have what it takes to be a champion, he’s going to be exposed badly by the hard hitting Rubio in this fight. Rubio is like the middleweight division’s version of knockout artist Corrie Sanders. Rubio hasn’t accomplished much in his 12-year pro career in terms of winning world titles.

He’s been kind of an erratic fighter that looks good in knocking guys out but who has failed in important fights against Kassim Ouma, Zaurbek Baysangurov, Kofi Jantuah and Kelly Pavlik. Rubio’s problem is that if he isn’t able to get his opponent out of there, he becomes vulnerable to losing by decision. He’s first and foremost a puncher and that’s how he wins loses his fights. He’s what you would call a top of the line model slugger, as he’s got passable boxing skills to go with crushing power.

Rubio will have to get past Chavez’s jab to get in close enough to land his big power shots. Chavez Jr. hasn’t been one to use his jab in the past and has preferred to work in close in a poor copy of his famous father’s style of fighting on the inside. However, in Chavez Jr’s last couple of bouts, his trainer Freddie Roach has succeeded in getting Chavez Jr. to use his jab much more as well as using movement to evade attacks. The last two fights were against non-punchers Peter Manfredo Jr. and Sebastian Zbik.

Chavez Jr. didn’t need to move and jab as much against those guys because he had a big size and power advantage in those fights. However, Chavez Jr. is going to have to move a lot against Rubio if he wants to escape the first half of the fight without getting knocked out. But the danger doesn’t end there for Chavez Jr, because Rubio is just as dangerous in the second half of the fight as he is in the first. He is slightly more dangerous in the early rounds, though.

Chavez Jr. will have to be able to use his jab in the last half to keep Rubio from pounding him into submission. Chavez Jr. has rotten stamina and often is gassed out completely by the 10th. The thing is you can’t gas out against Rubio because he’s not one of Chavez Jr’s B level opponents that couldn’t do anything with him when he faded late in fights. Rubio will do something and it will involve putting Chavez Jr. on he canvas if he can’t continue moving in he late rounds.