IMO Struve and Hunt need to beat at least 1 Top 10 fighter before getting a shot.
Werdum is fighting Big Nog in summer I think. If he wins, he would need like 4 or 5 months to prepare. That means that Cain will not be fighting until november? That is a very very long time.
If there is really no option, then make Cigano vs Cain III. Makes no really sense because JDS has to earn the rematch, but seriously there is no opponent that makes sense for Cain right now. Only Cormier, but they are teammates.