Rousey, 27, is well-aware that there might be a bit of a letdown from her last fight, as far as pay-per-view sales go.
Rousey last competed on the historic UFC 168 card, which featured a highly-anticipated fight between Anderson Silva and Chris Weidman.
Rousey's fight against Miesha Tate was also a big draw on the UFC 168 card, as it had been hyped up for over a year with back-and-forth trash-talking and also a reality show.
Naturally, there's not as much hype behind UFC 170.
UFC fans saw Rousey compete just two months ago and there's no real rivalry for fight fans to get invested into for her bout with Sara McMann.
"I have my concerns. It's a really quick turnaround on pay-per-view, so I really haven't given people a chance to miss me, after two huge PPVs, the Super Bowl card and the New Year's card," Rousey said. "When I'm on as the headliner, all the pressure does fall on me to deliver."
"I do worry about these things. It's like, the number one issue in front of me is the fight. The pay-per-view is second. I have to do what's best for me in the fight to win. I've talked to Dana [White] about whatever concerns I do have. He says its [White's] job to sell PPVs, just worry about winning the fight."
Analysis: There hasn't been much hype surrounding the UFC 170 card, but Rousey has nothing to worry about.
In all likelihood, UFC 170 will get a major push on Friday afternoon and then fight fans will be buzzing about the event by Saturday morning.
UFC 170 won't sell one million pay-per-views like UFC 168, but it'll end up about equal with other recent UFC pay-per-view buys.
UFC 168 should end up selling close to 450,000 pay-per-views, which was approximately the number Rousey hit for her UFC debut.