Diaz who is 24 years old recently lost his WBA, WBO and IBF title belts to Nate Campbell on March 8, 2008. The defeat was his first of his career in the bout Diaz suffered a severe cut over his left eye which was caused by a head butt, the cut effected Diaz's vision throughout the bout. Diaz reports that now his left eye is completely healed after a minor procedure was performed to elevate an infection as Diaz describes to us the cut and his “stubbornness” by not listing to his corner caused him to lose the fight. Diaz says he got away from his usual fight plan which includes jabbing and a flow of combinations instead Diaz stayed inside and Campbell has able to land some solid shots. Two of the three judges scored the bout for Campbell giving him the split decision victory.
Diaz informs us that his next bout is scheduled for September 6, 2008 against Michael Katsidis. The fight is going to take place at the Toyota Center in Houston, Texas which is Diaz's home city the only detail left is for both fighters to officially sign the contract. This will be Diaz's return to Houston after not fighting there for 3 years and he views this as a big home field advantage. Diaz takes great pride in being a champion, understands the dedication required to regain his belts. Diaz is not only committed to getting back the championships, he is also a full time student who over the next year or so will be graduating from the University of Houston where he is a pre-law major. According to Diaz his daily routine includes an early rise and straight to the 24/7 Wellness Center where he starts his day with weight training followed by Swimming and then off to the University, Diaz is so committed in graduating he even enrolled in Summer Classes. At night Diaz will hit the gym again to wrap up his workout for the day on the stair-master. This daily workout routine which differs from the normal boxer's workout plan is devised by his strength and conditioning trainer Brian Caldwell. With all this going on Diaz finds time to study in order to maintain good grades, after graduating Diaz who is Mexican, American plans to go onto Law School. He ultimately would like to be involved with either Immigration Law or Sports Contracts. Diaz like former Mexican boxing champion and Hall of fame inductee Carlos Palomino will be one of the few champion boxers that hold a college degree. Actually, Palomino on January 21, 1977 fought against Armando Muniz, this was the first time two boxers with college degrees fought for a world title.
Diaz who started to learn how to box at the age of 8 had a significant amateur career compiling a 105-5 record however he was prohibited from competing for the Mexican Olympic team in 2000 since he was not of age. Not wanting to wait another four more years Diaz turned pro and went on to win his first professional bout on June 23, 2000 at the age of 16 defeating Rafael Ortiz with a first round knockout. Since his first bout Diaz has won 32 bouts and has a record of 33-1. Now Diaz looks to pick up his winning ways against the tough Michael Katsidis who hails from Toowoomba, Australia. Katsidis (23 -1) (20KO's) is also coming off his first lose in which he was knocked out by Joel Casamayor in the 10th round. Diaz says he has started to study film of Katsidis and along with his long time training team or Ronnie Fields and Derwin Richards they will develop a top notch game plan. Diaz who was devastated about losing his title belts understands that he most look forward and needs to go on with his career. A victory over Katsidis will put him back in the lightweight title hunt which, besides Campbell and Casamayor includes the up and coming talented Anthony Peterson and Amir Khan.
After the Nate Campbell bout Diaz switched promoters from Don King to Oscar De La Hoya's Golden Boy. Juan says the switch was for the better now he is with promoters that care about their fighters and guide them to the correct match ups. Golden Boy unveiled Diaz at the April 19th Joe Calzaghe – Bernard Hopkins fight in Las Vegas. Diaz was part of the weigh-in event and shared the stage with many great fighters and celebrities. As legendary ring announcer Michael Buffer announced each celebrity to the stage Diaz was sure to remind Buffer to announce him as Juan Diaz “The Baby Bull”. Diaz is truly “The Baby Bull” with an undisputed work ethic and a never give up attitude 'The Baby Bull “is on life's right track.