The American fighter has not fought in the UFC since his no-contest against Anderson Silva in January 2015.
Incredibly, Diaz (26-9, 2 NC) has only fought four times inside the Octagon, compiling a 1-2 (1 NC) record with a notable win over BJ Penn that set him up for a shot at the vacant UFC interim welterweight title against Carlos Condit.
The 37-year-old lost that fight by unanimous decision. The Nevada State Athletic Commission also suspended Diaz for one year after he famously tested positive for marijuana after the fight.
But Diaz's manager Gracie, his longtime coach and trusted confidante, has confirmed that Diaz is back in training ahead of a possible comeback before the end of the year.
“We were looking at September,” Gracie said to MMA Fighting. “I have to see where he is in his contract.
"It is possible that his next fight will not be in the UFC. We are studying that possibility."
“Nick is very open to take [sic] a fight in MMA or boxing," he added.
Diaz is on a two-fight losing streak fight now and is 2-3 in his last five fights. Both of his most recent losses came against Georges St-Pierre and Carlos Condit - two all-time greats of the UFC's welterweight division.
Diaz's last appearance outside of the UFC was on April 9, 2011, where he came out on top against British slugger Paul Daley in an all-time classic scrap at Strikeforce: Diaz vs Daley.
But UFC president Dana White has done all he can to curb any enthusiasm ahead of a potential return to action as he questioned whether the 37-year-old still has the same burning desire to become one of the best MMA fighters in the world.
White, who recently announced plans to open a UFC Performance Institute in Africa, explained: "It’s just the amount of time that he’s taken off already.
"When you hear him talk about fighting, when you hear him talk about the sport – and I sit down daily, or talk to daily, hungry, young savages that want to break into the top 10, become world champions, all that stuff.
"Nick Diaz has done it all, seen it all. He’s been in big fights. I just don’t see that in him when I talk to him."
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