Eddie Alvarez interacts with fans and media during the UFC 205 press conference inside The Theater at Madison Square Garden on Nov 10, 2016 in New York City. [Photo/VCG]

Alvarez, 5-foot-9, 155 pounds, was a high school wrestler who had his eyes opened to MMA when he attended a UFC card in Atlantic City. He became hooked when he was introduced to a group of men training in a basement near his home.

"It wasn't even known, the sport wasn't really anything at that time," Alvarez said. "No one knew anything about MMA. But when I went, I said 'This is cool.'"

But not cool enough for him to stick with the sport in high school. After he graduated, Alvarez was directionless and spent his weekends with the wrong crowds and getting mixed up in fights - the kind that could have landed him in jail, not prepping for title shots.

"Sooner or later I was like, 'I need to go see those guys that went down in the basement'," Alvarez said. "I needed to see if they were still training, and they were. Except now they had a gym."

Alvarez made his pro debut after just eight months of MMA training.

He went undefeated in his first 10 MMA fights and won the Bellator Fighting Championship's lightweight title in 2009. He became entangled in a protracted legal conflict with Bellator and eventually signed with UFC in 2014.

Alvarez was trounced by Donald Cerrone in his first bout, but recovered with split-decision wins over Gilbert Melendez and Anthony Pettis to earn a lightweight title shot.

Alvarez won the 155-pound title with a dramatic first-round stoppage of Rafael Dos Anjos in July on a UFC Fight Night card.

Up next, McGregor, who is coming off a decision victory against Nate Diaz in a welterweight bout in August at UFC 202.

"A lot of people are going to show up to watch me beat this guy up - and that's just what they're going to see" Alvarez said.

McGregor said this week he would "retire" Alvarez.

"It's over for you. You will not fight again after this," McGregor told him. "You will not look the same. You will not think the same, and that's it."

Alvarez laughed off the threat.

"I'm about to take out arguably the biggest name in MMA," he said.