On Wednesday, the 32-year-old reiterated the reasons behind his extended absence. For starters, he says he doesn't see any available opponent worth his time.
Speaking to MMAFighting.com, Diaz said the UFC has been "stagnant" in 2017 and is in need of its biggest stars. He listed McGregor, Jon Jones, Ronda Rousey, his older brother, Nick, and himself as the only real needle-movers in the sport.
"There's not s--- going on in [mixed martial arts] right now, everything's kind of boring," said Diaz on The MMA Hour. "Everybody's complaining, as they should be. It's getting stagnant out there. They need to talk about the hottest s--- in the game, which is me and my brother."
That said, Diaz (19-11) indicated he has no plans to step back into the Octagon soon and would be fine sitting out all of 2017 to focus on his hobby of competitive bike racing.
The Stockton, California, native said the UFC offered him a fight against Tony Ferguson (22-3) at UFC 213 on July 8 in Las Vegas. Diaz said he initially accepted the fight, but it fell through because of certain "circumstances" he demanded.
He also said he doesn't like the idea of handling McGregor's "dirty work" while the Irish star pursues a lucrative boxing match against Floyd Mayweather. McGregor is the UFC's lightweight champion, and Ferguson is widely seen as the division's No. 1 contender. They also are represented by the same agency, Paradigm Sports Management.
"I gladly accepted [the fight], and then it was gladly rejected," Diaz said of a Ferguson bout. "[I said,] 'Sure, I'll fight him, but under these circumstances.' Then I was ignored. Then rumors went on. I asked, 'Why are rumors still going on if it's not popping?'
"Then I thought, 'Why am I going to do Conor McGregor's f---ing work for him? No. You two fight each other, then you get a chance at the golden child right here, you know what I'm saying?'"
According to Diaz, he is not sitting around waiting for a trilogy fight against McGregor, despite popular belief. Diaz still feels he got the better of their two-fight rivalry last year. Diaz submitted McGregor in the second round of a welterweight fight at UFC 196, before dropping a majority decision to him at UFC 202.
"If I got my ass whupped by somebody, I don't just win a slight decision and accept it," Diaz said. "The real champ is right here. And [McGregor and Ferguson] can fight each other and then light a fire under my f---ing ass [to take the fight]. Or if someone wants to make a scene and make a star of themselves and get me to fight, then step your game up and become a star."
As far as McGregor's potential boxing match with Mayweather, Diaz said he wants it to happen. He, like many others, probably wouldn't mind seeing it happen sooner rather than later, though, to clear some air in the UFC.
"If Floyd beats Conor, who the f--- gives a s---? I already whupped Conor's ass. So, you beat the guy I already beat up," Diaz said. "If Conor beats Floyd, then the guy whose ass I whupped just beat Floyd Mayweather. So, it's great. I'm calling your bluff. Make the fight happen already. Let's see this s--- pop off. I'm ready to go. I've got winner, if anything."
McGregor (21-3) has not fought since he won the lightweight title in a knockout victory over Eddie Alvarez at UFC 205 in November. He is currently in Dublin awaiting the birth of his first child.