By Dan Ambrose: If you looked at how big WBC middleweight champion Julio Cesar Chavez Jr. (46-0-1, 32 KO’s) was compared to his last opponent Andy Lee last month in their fight at the Sun Bowl in El Paso, Texas, you might think that Lee was fighting a light heavyweight rather than a middleweight.

The weight was never given for how much Chavez Jr. weighed on the night of the fight with Lee, but he looked at least 180 lbs in the view of HBO analyst Roy Jones Jr. Since Chavez Jr. has been coming into his fights weighing approximately 180 for his last five bouts, it’s definitely been a plus for him against his smaller opponents, who haven’t rehydrated up as high as Chavez Jr. has after making weight.

Battling an opponent that you have a big weight advantage over is a real plus for the heavier fighter. Chavez Jr. hasn’t been affected by his taking off and putting back on water when making weight. He’s lucky in that respect I guess, because few fighters can take off and put 20+ pounds of water without being substantially weakened in the process.

Chavez Jr. will be facing his toughest fight of his career against former WBC middleweight champion Sergio Martinez (49-2-2, 28 KO’s) on September 15th in a pay-per-view bout on HBO at the Thomas & Mack Center, in Las Vegas, Nevada. This is the fight where Chavez Jr. will proves if he’s a world class fighter or not, because it’s still hard to tell because of him being so much heavier than his opposition. There are fighters that beat their opponents with speed, power or skills. Then there are others that beat their opposition with size alone. Chavez Jr. fits into that category by coming into his fights weighing so much on the night of his fights.

The question is whether Chavez Jr. at 180 lbs will be able to overcome Martinez’s speed, power and skills advantage for their fight. Chavez Jr’s size is pretty much the only thing he has going for him in this fight, and it’s going to be interesting to see if it will be enough for him.