#2 Samoa Joe
Samoa Joe is the current United States Champion. Joe won the championship in a fatal four-way match involving Rey Mysterio, Andrade, and R-Truth. Joe was rumored to face John Cena at WrestleMania, but now it appears that those plans have changed.
As of now, Samoa Joe does not have an opponent for WrestleMania 35, unless WWE decides to go with the fatal four-way route again. The only problem is, that match has already been done two times in quick succession. A fresh match would be better for everyone.
Joe and Owens faced each other in their NXT days but the two never got a chance to have a proper feud going at NXT due to Owens being called up to the main roster. This would be the perfect opportunity to rekindle the feud between the two.
Both of the superstars have a history going back to their indie days and WrestleMania would be the perfect time for them to showcase it in front of the WWE Universe.