And for Donald Cerrone, after having fought dos Anjos in 2013 and watched him truck through Anthony Pettis in May, let's just say that "Cowboy" expects to see a different version of the Brazilian when the two rematch in Orlando.
"His strength, oh, it's going to be a different strength," Cerrone told MMA Fighting. "We have USADA testing now, so it's going to be all different. It's a whole new animal. I don't dwell on the last fight or anything, it's a whole new thing. I'm going out there, I'm looking to finish him, man. So the first round and second round, I'm coming out f**king hard."
Dos Anjos has been randomly tested four times in the fourth quarter of 2015 according to USADA's official UFC database, which was last updated Dec. 10. And while the lightweight champion has never before failed a drug test, Cerrone isn't shying away from his statements.
A chiseled and unrelenting dos Anjos captured the title with a dominant performance over Pettis at UFC 185, despite entering the fight with a torn MCL in his knee. Now, after having seen a slow trickling of fighters shrink down to a smaller size since the UFC-USADA partnership began in earnest in July, Cerrone believes that many observers will be surprised by the changes they see from his opponent on Dec. 19.
"Absolutely, dude," Cerrone said. "You see it a lot. Not dropping any names, but you've seen a lot of guys: ‘oh, wow, you look different... and your cardio is different. And you can't walk through those punches like you used to.'
"So I like it, I'm 100-percent for it. It sucks that we're too that point where we have to test people and that there's no honesty, but hey, let's make it an even playing field, absolutely. Test me everyday if you have to."
UFC on FOX 17 closes out what may be the UFC's most successful year ever, however the wait to fight night has been a long one for both fighters. Nine months have passed since dos Anjos seized the lightweight title, and Cerrone has been sidelined for seven.
For a guy like Cerrone, who is accustomed to fighting as often as possible, the time on the shelf has been near torturous. He picked up a few new hobbies in the interim, namely scuba diving and base jumping, but now that the chance to finally challenge for the UFC title has arrived, Cerrone is prepared to thrust open a lightweight division that has stagnated under injuries and inactive champions over the last several years.
"(I'd want to defend the belt) as often as possible," Cerrone said. "A lot of the champs get hurt, they take a lot of time off. Nah, let's go. I'll defend it six times a year, I don't care. It makes no difference, I just want to keep fighting. That's why I love this. The training and the week of the fight, they're terrible. The actual fight, man? It's what I live for. I love it."
Cerrone may be confident, but he hasn't forgotten his first fight with dos Anjos -- a UFC Fight Night 27 meeting which he lost via unanimous decision.
Cerrone has won eight consecutive fights since that night, beating the likes of Eddie Alvarez, Edson Barboza, and Benson Henderson, and he vows that the "Cowboy" of Aug. 2013 is nowhere close to the "Cowboy" of the present day.
"[Dos Anjos] is definitely going to try to take me down. You know what he did to Pettis, he's going to try and do that to me," Cerrone said. "I'm a lot more dangerous on my back than Pettis. I truly believe I'm better than dos Anjos everywhere. Standing, wrestling and jiu-jitsu. I'm sure he's going to take where I want to take the fight and what I want to do. So what I'll do with him, man, I'm 1000-percent confident in myself. Cerrone, by f**king head kick."