"I'm a whole different animal. Back then, I was a kid with big balls. There was a general overall knowledge of a lot of things, but now it's a whole different story. I'm a way more polished, calculated and a sharper fighter overall. I'm a different animal, and especially for this fight – you're going to see the best middleweight in the world."
Vettori has been on a dominant run in the middleweight division since that loss, with five wins in a row. His list of scalps includes fellow top 15-ranked fighters Jack Hermansson and Kevin Holland. During that time, Vettori has displayed his full arsenal of skills, with his high-pressure and heavy wrestling common features in his performances.
The 27-year-old, who is looking to become the UFC's first Italian-born champion, was the second option for the bout, with Kiwi-born Australian Robert Whittaker passing up the opportunity for a rematch against Adesanya as it would have been too short a turnaround between fights for him.
But while Vettori was the UFC's second choice for the fight, he said all he needed was another opportunity against Adesanya - and the fact the upcoming bout would be contested over five rounds would only work in his favour.
"I love the five rounds" Vettori said. "I think the quality of the fighter comes out in the five rounds. I think [it favours] me, because he'll have to worry about so many things.
"But I'm really looking to finish this fight. Any time, at any moment, it could end."
The bout will be one of two to feature a New Zealand athlete on the UFC 263 card. Lightweight Brad Riddell will take on No 13-ranked Drew Dober earlier in a striking clash sure to please the fans.