Conor McGregor has been accused of ‘putting steroids and all kinds of things in his body’.
Masvidal told ESPN Deportes: “He is false. He knows that I am a man who hits hard and that I come to kill. I do not come to hug in the cage.
“I am going to give everything inside me to kill him. I have a little size, although now he’s shooting up and putting steroids and all kinds of things [in his body], but he is still a little boy.”
“I would love to fight at 170 pounds, but I don’t wait for anyone. If he wants to do it, I’ll break his face. If he doesn’t want to do it, let someone come next.”
Masvidal, 37, recently signed a new multifight deal with the UFC, making him one of the promotion’s top earners in the process.
The fan favourite hasn’t set foot inside the octagon since losing his long-awaited grudge match with Colby Covington at UFC 272 in Las Vegas.
He added: “There are options, but the first thing that matters is me.
“To be in the best condition of my life, to improve the fight, everyone knows that I can throw the hands, the kicks, the knees.
“People know that they cannot beat me with their hands, that they have to throw me into the fight, it is something that I have to improve and find the formula for.
“This year, guaranteed return, I don’t know the date yet. I think that with two fights I can be in contention for the title or in a title contender fight.”
Masvidal was recently charged with aggravated battery and criminal mischief after his alleged brawl with bitter rival Covington outside a Miami steakhouse in Florida.
He continued: “I come from a different place than many people and we walk differently in that place, I am not going to let anyone disrespect my family.
“I can’t talk much because I’m being charged with three felonies.
“I can only say that I am innocent.”