Most Valuable Prospects 12 is slated to go down on Friday ... and TMZ Sports has already done the heavy lifting for anyone wanting to track down the promotion's newest ring girl -- her name is Marissa Ayers, and we talked to her ahead of her big debut!!

We chopped it up with the MVP newbie and fellow models Delia Sylvain and Rapha Milagres ahead of fight night in Orlando ... and the rookie opened up on how she ended up in the family.

It turns out Rapha played a role in getting the Georgia native and Alabama student on board ... and after a few convos, she was handed her sparkly blue outfit and got to work as an MVP event model.

"I'm so excited that this is my first time," Marissa said. "This is something that is completely new to me, so stepping into a new chapter. I am so grateful to MVP and the team. It's been so amazing so far."

"Definitely an incredible opportunity and I'm excited to be with such an incredible team that stands for amazing things."

Rapha said Marissa fit the vibe of the MVP family ... and outside of being "a gorgeous girl," she could tell she stood for the same interests they have as a brand.

All three ladies opened up on how they're able to capitalize on the massive audience MVP events draw all the time ... especially with their own personal endeavors.

"I think it's also nice that we're able to formulate our lifestyle to what we do," Delia said. "We have a lot of appearance that we need to keep up with and our health and wellness. That's not just an event thing, that's kind of an everyday thing."

She also pointed out how the gig isn't for everyone -- as having the charisma to take over an entire stadium or live broadcast requires plenty of practice.

The MVP brand has welcomed celebrity guest ring girls like musician Saweetie in the past ... so when we asked who they'd like to see join the family next, Marissa had a quick response.

"Tate McRae."