Juan Diaz's return to boxing did not last long.

Two weeks after signing a contract to fight David Torres and announcing that he would end a one-year layoff, the former unified lightweight titlist withdrew from the fight Tuesday, telling promoter Leon Margules of Warriors Boxing that he was instead going to attend law school.

Diaz, 27, of Houston, had signed to fight Torres in a scheduled 10-round lightweight bout at The Cosmopolitan in Las Vegas on July 29. The fight was scheduled to headline ESPN2's "Friday Night Fights."

Diaz, a graduate of the University of Houston Downtown, had recently been accepted to the University of Massachusetts Dartmouth Law School. He has talked for years about someday going to law school, but the lure of the ring seemed like it was too much.

"I have the acceptance letter from law school and I look at it every day and question myself every day if I am making the right decision," Diaz told ESPN.com two weeks ago when he announced his comeback fight. "I put it to the side and say law school can wait. What I really want is to become champion again, so I've been emailing back and forth with the university to see if I can work something out where they will let me defer for a year because I don't think I want to go yet."

Diaz (35-4, 17 KOs) did not get the deferral and had a change of heart.

Willie Savannah, Diaz's manager, faxed a hand-written letter to Margules telling him of Diaz's decision.

"He had trained 4-5 days per week for months in anticipation of once again becoming a world champion," Savannah wrote. "He made this decision last Friday and I support it 100 percent. I hope that Warriors and ESPN will understand.

"Diaz does not have a history of pulling out of fights like a lot of boxers do. I apologize for the inconvenience this will cause all parties."

Diaz was going to attempt to return two days shy of the one-year anniversary of his last fight, a clear decision loss to lightweight champ Juan Manuel Marquez in a rematch. Diaz, who was knocked out by Marquez in the consensus 2009 fight of the year, was 2-4 in his last six fights and his career was clearly on the ropes.

But Diaz had told ESPN.com two weeks ago that he was refreshed and ready to make another title run.

"It's been awhile and I am very excited and very pumped about being back in the ring," Diaz said. "Last time I fought was July 31 last year, so it's going to be a year. So I'm looking forward to fighting again and showing people what I still have."

Diaz was only 20 when he claimed his first world title in 2004. He made seven defenses, including unifying three major belts with wins against titleholders Acelino "Popo" Freitas and Julio Diaz, before losing them in an upset decision to Nate Campbell in March 2008.

Margules told ESPN.com that he hopes to replace Diaz-Torres with a light heavyweight match between Colombian slugger Edison Miranda (34-5, 29 KOs), a former middleweight and super middleweight title challenger, and Yordanis Despaigne (8-1, 4 KOs), a former Cuban amateur star.

Margules said both fighters have agreed to the fight and he was awaiting the go-ahead from ESPN to finalize the contract.

Last Saturday, Miranda ended a 14-month layoff following a third-round knockout loss to super middleweight titlist Lucian Bute. Miranda easily outpointed Rayco Saunders in an eight-rounder on the Carl Froch-Glen Johnson undercard in Atlantic City, N.J.

Despaigne is coming off a 10-round decision loss to fellow former amateur star Ismayl Sillakh on ESPN2 in March. Although Despaigne has just nine pro fights, he had a deep amateur career for the powerhouse Cuban national team, including beating future light heavyweight champion Jean Pascal during the 2004 Olympics.

The opening televised fights remains intact: former lightweight champion Joel Casamayor (38-5-1, 22 KOs) against Jorge Teron (25-2-1, 17 KOs).

Dan Rafael is the boxing writer for ESPN.com. Follow him on Twitter @danrafaelespn.