Holm, a former world boxing champion, has seemingly been on a collision course with Rousey for several years. Both are undefeated. Holm's background as a two-time fighter of the year in The Ring magazine makes for an intriguing prefight buildup.
Still, Holm (9-0) was surprised to hear she was already next in line. She had previously accepted a fight in December against Sarah Kaufman, and the UFC had announced Rousey was fighting Miesha Tate next.
"It was definitely a surprise," Holm told ESPN.com. "I had already accepted a fight. I got a call Tuesday night from my manager. He said he just got off the phone with [UFC president Dana White and CEO Lorenzo Fertitta] saying that fight was off and we were getting Ronda. So it was shocking because I was already committed to another fight. Fighting for the title was the last thing on my mind."
Holm, 33, retired from professional boxing in 2013 to focus exclusively on mixed martial arts. She finished with a 33-2-3 record, including nine knockouts.
Fighting out of Jackson-Winkeljohn MMA in Albuquerque, New Mexico -- home to former light heavyweight champion Jon Jones, welterweight title contender Carlos Condit and flyweight title contender John Dodson, among others -- Holm is 2-0 since signing with the UFC.
Both of her fights in the Octagon have gone the distance. She defeated Raquel Pennington via split decision in her promotional debut in February. In July, she scored a unanimous decision over Marion Reneau. ESPN.com ranks Holm the No. 9 bantamweight in the world.
Holm spoke in-depth to ESPN.com about the championship fight, which is scheduled to headline UFC 195 at the MGM Grand Garden Arena.
This matchup came as a surprise to a lot of people. Any idea how/why you leapfrogged Tate to get the opportunity?
"I'm one of those who asks the least amount of questions. When it comes to that, I don't ever question what the UFC does. That's why they run the promotion. They call me and I say, 'OK, let's do it.'"
After you get that call, what's the first thing that goes through your head? Is it complete confidence right out of the gate? Is there a hesitation, like, "Am I ready for this?"
"My initial reaction was, 'I can do this, I can do this. I can make this happen. It's just going to be a lot of work. I just need to focus on preparing myself.'"
In the buildup to this fight, you are likely to hear a lot of people say, "It's just too soon for Holm. This opportunity is coming too quick. She needed more time." What is your reaction to that?
"Yeah, I think that's probably going to be the biggest thing. I don't feel like people don't necessarily believe in me, but they do feel it's too soon. But that's them and not [me]. There's a reason I'm fighting for this title and they're not. People are going to say what they want, and I don't even blame them for feeling that way. I'm going up against the most dominant fighter. Why would they think I'm going to win? But like I said, that's also why they're not the ones doing it. I'm the one who has to go in and take this seriously and believe in myself."
Your accomplishments in the boxing ring speak for themselves. Is that the greatest challenge you pose to Rousey and something she maybe hasn't seen from anyone else yet?
"My biggest thing is styles make a different fight, and this will be a fight that's not going to be anything like what she has been in before. She has definitely proven herself in every way, not just with the armbar, which everybody always talks about. Ronda has been able to use her hands as much as her ground game. You can't call her knockouts lucky. She has landed knees to the body and the overhand right to the temple of these girls. People ask me if she has gotten lucky. No. That's called skill, determination, ambition. She gets in there and believes she can do it and she does. That's the biggest thing I have to face. She's definitely going to be tough but I have my skill, my drive, my belief in myself. I feel like I've put the time in."
This fight was just announced, but you've obviously had your eye on Rousey for quite some time. Have you been sort of training with her in mind since you got into this sport?
"Every person always says, 'Oh my gosh, you better be working your armbar defense.' I'm working all of it. You don't get to an armbar by just lying there. It starts from different positions, someone closing distance, working a throw -- we're working on all those steps along the way to the armbar, not just the armbar defense. I don't even want to be in that position in a fight. And I don't want to get caught up too much in one angle of the fight. That's one thing that's different from boxing: There are so many different angles when it comes to how a fight can pan out.
You are preparing to be better than Rousey in every area, but given your background, when you visualize the end of this fight, is it safe to assume it's you winning by knockout?
"I always visualize knockouts. And I visualize them in different ways. I never put it in my mind that's what is for sure going to happen, because I feel like if I say, 'I'm going to knock her out in Round 3 -- well, if that doesn't happen, then I'm not ready to fight rounds four or five.' I train for the full fight. That definitely could be the way it goes. I visualize openings, especially when I'm running. That's when I do it most. It is definitely something I'm constantly thinking about, but it's not something I put all my eggs into one basket."