In an Instagram post that went up Tuesday night (warning: contains NSFW language), the 32-year-old teased that he will be ready to fight sometime late in the spring.
"Sick of sitting around waiting for you f–kers to do s–t there's no excitement in this fight s–t step your games up I'll see u around may, June," he wrote. "Sincerely The Real Champ."
Citing sources, MMA Fighting's Marc Raimondi reported Diaz "is ready to fight again in the timeframe mentioned."
Diaz, who's 19-11 lifetime, hasn't fought since he lost to Conor McGregor via majority decision at UFC 202 in August 2016. Five months earlier, Diaz stunned McGregor via second-round submission (rear-naked choke) to intensify the rivalry.
Rumors previously circulated regarding a potential trilogy clash between the two, but UFC President Dana White quickly shut them down.
McGregor—who stepped away from UFC last year to fight Floyd Mayweather Jr. in a boxing match—was last seen in the Octagon in November 2016 when he defeated Eddie Alvarez via second-round knockout to secure the lightweight title.
According to the Daily Express' Chisanga Malata, White recently disclosed McGregor is "thinking about coming back in September."
In the meantime, interim lightweight titleholder Tony Ferguson and Khabib Nurmagomedov will prepare to square off at UFC 223 on April 7.