Kayla Harrison vs. Amanda Nunes is off, but that doesn't mean The Lioness' Octagon return has to be put on hold ... boxing star Amanda Serrano tells TMZ Sports she's ready to step in, and she's dead serious!
"I'm up for the challenge. I'm always up for the challenge," 37-year-old Serrano told Babcock about the prospects of fighting Nunes, a "great champion" and "great fighter."
What would Serrano say to the fans who will undoubtedly claim that while she's a beast in the squared circle, this is MMA, and Nunes is the G.