LAS VEGAS: Conor McGregor used to train whenever he felt like it, and he stayed up late every night. He would sleep deep into the daylight hours, and he perpetually showed up late for almost any commitment required of a rising mixed martial arts star. McGregor had reason to believe chaos was his natural environment: He was climbing to the pinnacle of the so-called combat sports, winning two UFC title belts and earning an absurd payday against Floyd Mayweather while becoming the most famous fighter in the world. But McGregor knows the chaos gradually caught him and consumed him. The last half-decade of McGregor’s public life has been an exhausting stretch of competitive disappointments and continuous legal troubles, including at least three violent confrontations outside the cage. His side career has been more successful than his endeavors in a boxing ring or a cage, where he has competed just twice — and hasn’t had his hand raised in victory — since 2016. “Consistency and structure was missing,” McGregor said after arriving a mere half-hour late to a UFC production facility in the Vegas desert. “Structure. I was sporadic with my work and with my life. I’m a lot more centered now, a lot more grounded and a lot more focused.” That means a regimented schedule for training, sleeping and eating. “With activity, with consistency and with structure, I can do anything, like I have done already,” McGregor said. Nearly 16 months after he lost to Khabib Nurmagomedov in his only mixed martial arts fight in over three years, McGregor (21-4) returns to the cage at T-Mobile Arena off the Las Vegas Strip against Donald “Cowboy” Cerrone, a fellow veteran brawler and UFC stalwart attempting to mount a comeback.