Claressa Shields still has Amanda Nunes squarely in her sights, and has taken steps to make the fight a reality ... telling TMZ Sports she's met with an MMA coach and her manager talked to Dana White.
Shields -- who's only 24 years old -- is a beast. She holds belts in 2 weight classes, and is looking to make history as the fastest fighter to be a champion in 3 different divisions.
Vasyl Lomachenko accomplished the feat in only 12 fights ... if Claressa wins her October 5 fight with Ivana Habazin, the record is hers.
That's not the only history Shields wants to write ... when we talked to Claressa on Friday, she told us she's seriously considering taking up MMA ... with the end goal being a Nunes superfight.
"I'm really a hard worker, and I'm dedicated to the craft. I eat right, I don't drink, I don't smoke. When you have an athlete like that, and I'm young, I can really pretty much do anything right now," Shield says.
"It has been thoughts to actually start training. I've actually sat and talked with an MMA coach. Shit can get serious real quick."
In order to make this happen ... Dana White -- who previously told us he's open to the idea -- needs to be on board, and Claressa says her manager has already talked to the UFC honcho.
Shields isn't just gonna jump from the boxing ring into the Octagon and fight Nunes, she says she needs to develop her ground skills ... and take a few warm-up matches.
"I'd like to get some fights and build my way up to that."