Five-time kickboxing world champion Kathy Long believes Rousey could not only compete, but she thinks the Strikeforce women's bantamweight champ would stand a good chance against UFC bantamweight men.
"I think if anybody's willing to go in and continue to train with men, they stand a good chance when fighting against men," Long said on "The MMA Hour" with Ariel Helwani. "When I was boxing as an amateur a long time ago, I only had males to fight against, and I won [against] all of them. So I think [Rousey] stands a good chance."
Rousey is noted for having trained with the Diaz brothers and Manny Gamburyan.
Still, there is something to be said about training and an actual fight. It's hard to envision Rousey or any woman taking damage from Renan Barao, Dominick Cruz or Urijah Faber. The overall physical makeup between men and women is different.
At 135-pounds, every UFC fighter in the bantamweight division would have a strength and speed advantage over Rousey.
Luckily, MMA isn't just about speed and strength. The most important aspect of fighting lies in technique, and Rousey's Olympic level Judo and ever-improving Brazilian Jiu-Jitsu skills give her a chance against all opposition, regardless of sex.
Long continues in her interview with Helwani:
"You know, all of my sparring partners were, and always have been, men, who are bigger, stronger and heavier than me. Because of that, I've learned to hit very, very hard, because I've had to. They were willing to beat the crap out of me, literally, and that's what made me who I am. That's how I got five world titles, because of all of my sparring partners. Did I hurt them? Yes. Did they hurt me? Yes."
It's a real possibility Rousey could beat amateur bantamweights and possibly even some lower-end pros.
As for UFC fighters, it would be tough for her to overcome the physical advantages held over her by some of the best fighters in the world.
Rousey is still one fighter you should never count out.
One mistake is all it would take to be the first man subbed and embarrassed in the Octagon with a first-round armbar.