Cyborg called out Rousey for years -- once telling TMZ Sports she wanted to kill the first UFC women's champ to end their soap opera ... but Cris says Ronda ain't worthy of the scrap anymore after a pair of brutal losses.
"When I wanted to fight her it was because she was at the top of her game and she had all of the confidence in the world," Cyborg said in a statement.
"She had not been KO'd twice in a row and some people were actually saying she could beat Floyd Mayweather in a fight."
"Both of us are now at different chapters in our careers and for me that chapter is finished."
Cris says she'd only take on Rousey in the WWE ring ... cause that's the only place they'd be on even ground.
Cyborg responded by saying Edmond's "nothing but a joke of a coach."
As for Ronda ... she's rumored to be transitioning to WWE after cutting a backstage promo earlier this month.