Miller is going to be at a striking disadvantage in this fight and Santos loads up on all her shots; she seems to hit relatively hard.
If Miller wades into the clinch with her head down like she has done in every single professional fight she is probably going to eat an overhand right from Santos and that could end the fight right there. Miller has looked somewhat rocked in every single fight I have watched of her. Sure she fights through it but she hasn't fought an opponent as agressive, somewhat recklessly at times, on the feet as Santos.
I took Santos KO/TKO at +1300 which also covers a GNP finish which I think is nearly as likely as a sub.