Attorney Jose Baez’s book on Aaron Hernandez has details behind his former client’s switch of jersey numbers during his time with the New England Patriots . (AP)

Famed defense attorney Jose Baez has a new book detailing his time representing Aaron Hernandez in his 2017 double-murder trial in Boston. Hernandez, a former star with the New England Patriots, was found not guilty of the twin killings but committed suicide days later while in a Massachusetts prison where he was serving a life sentence for the separate murder of Odin Lloyd.

There are a lot of stories in the book, “Unnecessary Roughness: Inside the Trial and Final Days of Aaron Hernandez,” including how in 2011 Hernandez sold his then jersey number (85) to new teammate Chad Ochocinco, and then used the money, $50,000, to float a wholesale drug purchase which later made Hernandez $70,000 in profit.

Even by the chaotic standards of the NFL, this sounds like something the HBO show “Ballers” would reject as a plot point too outrageous to believe.

It starts with Baez saying Hernandez had relatively little money early in the football player’s pro career. Despite being a first-round talent during his time at the University of Florida, a series of off-field incidents and failed drug tests caused Hernandez to fall to the Patriots in the fourth round of the 2010 NFL draft.

That draft slot earned him a base salary of $320,000, and combined signing and roster bonuses of $276,000. That’s great money for the average American, especially a 21-year-old, but with agent fees, training costs and taxes, not to mention living a large lifestyle, Hernandez complained he was often “broke as [expletive],” according to Baez.

“I can’t tell you how many times I’ve gone out to eat or drink with teammates and didn’t have the money to cover the bill,” Hernandez told Baez, according to Baez.

Baez writes that this is a common problem with young athletes he has represented and it is why “many [athletes] turn to the drug trade” by “floating” money to dealers they know. The drug dealers buy product at a bulk rate and then sell on the street, cutting the player in on the profits, according to Baez.

“All they have to do is hand the money to someone they trust and wait for the return,” Baez wrote.

View photos Aaron Hernandez gave up his No. 85 jersey after his rookie season. (Getty) More

Hernandez didn’t have the money to float a drug dealer until after his rookie season when the Patriots acquired Ochocinco in a trade. The veteran wide receiver was originally known as Chad Johnson, but he changed his last name to the Spanish word for 8-5, which was his jersey number in Cincinnati.

Hernandez wore 85 with New England as a rookie and saw an opportunity.

“Aaron figured Ocho Cinco [sic] might want to wear number 85 with the Patriots so he approached Ocho Cinco [sic] and offered to sell him the number for $75,000,” Baez wrote. “Mr. Cinco balked at the price and countered with $50,000. Aaron accepted, gave him the number, and went back to the number 81 he had in college. Aaron took the money and floated it to his cousin’s husband, T.L. Singleton, who gave Aaron back $120,000.”

Ochocinco and Hernandez told ESPN in 2011 that no money was exchanged. “We’re playing at a high level, so all of us have a decent amount of money. I definitely should have [asked for compensation], but I didn’t,” Hernandez told ESPN. “It was just a welcome to the team. … I thought he may look better and play better in 85, because that’s his last name. So why not give it to him?”

Said Ochocinco at the time: “It was Mr. Hernandez’s way of greeting me here. He gave me the number, I didn’t have to pay anything.”

If Baez’s account is true, it was a nice return on investment for Hernandez. Supposedly Hernandez and Singleton didn’t specifically discuss the exact purpose of the float. Hernandez originally denied it was for drug sales to Baez, before finally copping to it.

“Okay, I knew what he was going to do with it, but it was not something we ever spoke of,” Hernandez said, according to Baez. “He just paid me back.”