Shinsuke Nakamura vs Rusev - US Championship
Shinsuke Nakamura has been largely absent from WWE programming as of late, and a big reason for that may be his contract, which is reportedly set to run out at the end of January.
If that is the case, and he doesn't re-sign with the company, then you can expect him to be dropping the belt sometime before then.
The best opportunity for him to do so would be at Royal Rumble, with the most viable candidate for the gold right now being Rusev.
Despite a lack of development in recent months, Rusev is still one of the most over faces on SmackDown and the Bulgarian Brute has an impeccable record as US Champion.
The US belt has become anonymous since Nakamura won it this Summer, and Rusev could be the perfect man to help make it relevant again.