The former UFC heavyweight is concerned with Rousey's current mental state, saying the fighter may not be over her demons, given the amount of time she has taken to get back on the horse in chase of her title.
"You look at a real fighter like Conor McGregor. When he lost to Nate (Diaz) he was like, 'I want to fight tomorrow. Give me that f***** fight back man'," Schaub said.
"His team was like, 'don't take that fight, it's a bad fight for you'. He was like, 'No, I'll do it at 170 pounds. Just to prove to the doubters that I can do it' - that's what you want out of a fighter."
Rousey has been noticeably absent from the media rounds in the lead-up to the Las Vegas event. The star has previously pointed to media obligations being her undoing in her defeat to Holm, with outside commitments preventing her from remaining focused on her training camp.
But it's a rare interview that Rousey recently completed that has Schaub most concerned. Rousey appeared on Ellen days after the Nunes' fight was announced, where she said she does not plan on continuing in the sport forever and this will be one of the last times we see her compete.
That claim should be enough to ring alarm bells according to Schaub, who questions her commitment to the sport.
"What scares me about Ronda, she went MIA, she blamed it on the media. Well that same media turned you into who you are. Her taking this time off, it's a little scary," Schaub said.
"She also said something like this is one of my last ones. Whenever a fighter even hints that this might be the last one, they're one foot in, one foot out, or both feet out.
"When they say that, they get annihilated. If I hear that, I always take the other guy."
Despite his concerns over Rousey's mental state and commitment to mixed martial arts, Schaub still thinks Rousey will take her title back off Nunes on Saturday.
Schaub says the matchup is a good one for Rousey, as it hides her striking ability, which he says has now been exposed. "I wouldn't say her striking is world class. If she lands, she's a strong girl, you're in trouble. But Amanda Nunes is a knockout artist, that's the difference," Schaub said.
"Style-wise this fight is a good one for Ronda to come back for. Nunes comes forward and Ronda can throw her around and submit her. My money is still on Ronda, that's banking on her mental state being good. But from what I hear and with the time off, that's up for debate, which is scary."
