Kayla Harrison Says She'd Fight Pena, Pennington, Vieira All In Same Night

Kayla Harrison is locked in on her UFC 307 opp Ketlen Vieira ... but the 2x Olympic gold medalist tells TMZ Sports she's SO prepared, she's ready to also kick both Julianna Peña and Raquel Pennington's asses, too -- same night!

We caught up with the UFC bantamweight contender this week ... ahead of what'll almost surely be a title eliminator when she squares off with Vieira in Salt Lake City on Saturday night.

While she is not scheduled to face Pennington or Peña ... Harrison said she's heard that if either the champ or challenger drops out of the title fight, she could be called upon to step in.

"It's the fight game anything can happen," Kayla said. "For whatever reason, I just have this weird vibe. I'm prepared, I'm ready."

Pennington is preparing for the same outcome ... recently saying in an interview she, too, has been training to fight both Julianna and Kayla.

Harrison isn't phased by that one bit ... saying she's ready to roll with the punches, even if it means taking three fights at 307.

"I'm ready for it all," she said. "I'm ready for all three in the same night!"

That obviously isn't an option ... Harrison will fight once on Saturday. But, multiple fights in one night is how the UFC started. Just look at UFC 1 ... when Royce Gracie fought three times.

We also caught up with the current champ, as well, to get her thoughts on her title defense against Pennington. Julianna broke down what comes next assuming she walks away with the win, saying she'd like to settle the score with none other than the G.O.A.T., Amanda Nunes!

"I do believe Amanda will most likely be there," Pena said. "I do believe she will have that little green envious monster poking its ugly head out because she feels like she's not done. She's not ready to be retired, and she wants to be back in there because she's probably sitting at home thinking, 'What am I going to do today.'"