By Jason Kim: With a November mega fight with World Boxing Organization (WBO) welterweight champion Manny Pacquiao pretty much in the bag now, WBA/WBO lightweight champion Juan Manuel Marquez (52-5-1, 38 KO’s) is slated to fight 34-year-old former IBF lightweight champion David Diaz (36-3-1, 17 KO’s) on July 2nd in a 12 round bout in Las Vegas, Nevada. The soon to be 38-year-old Marquez wants the tune-up bout to stay sharp for the Pacquiao fight.

However, the fight could prove to be a bad one for Marquez, as Diaz is a slugger and he could either make Marquez look his age or end up cutting him. A bad cut would almost surely cause Marquez’s November fight with Pacquiao to be cancelled. It might prove a costly fight for Marquez if he does face the fading Diaz. As things are, Diaz has lost two out of his last four fights and hasn’t exactly been the most active of fighters in the past three years.

Indeed, Diaz has fought only three times since being stopped by Pacquiao in the 9th round in June 2008. Diaz was able to beat Jesus Chavez in his next fight after the Pacquiao loss but then was soundly beaten by Humberto Soto in March 2010. Earlier this year, Diaz went life and death in beating the servicable Roberto Frankel in a narrow 10 round majority decision win in January 2011.

Marquez hasn’t fought since defeating the made to order Michael Katsidis last November by a 9th round stoppage. It was an easy win for Marquez, except that he was dropped in the 3rd round from a big left hook by Katsidis. That’s a not a good sign it shows that Marquez is getting older. Diaz could give Marquez a lot of problems and may hurt the Pacquiao fight if Marquez has to struggle to beat Diaz. The fight will likely be shown on HBO, so it isn’t like it’s going to be an invisible fight for boxing fans.