Alberto Del Rio was left without an opponent for the 2016 edition of the WWE Royal Rumble when John Cena was forced out of action with a shoulder injury. But it didn't take long for a new challenger to step forward, thanks mainly to an upset victory at WWE Smackdown.

The new challenger is Kalisto, one half of the popular tag team Lucha Dragons. Del Rio and Kalisto were at it at Smackdown and the high-flying Kalisto was able to pull off a win from his fellow Hispanic star.

It remains to be seen if Kalisto can duplicate that feat at the Royal Rumble, though at this point, anything is possible.

Kalisto is one wrestler who has long been mentioned as a WWE star that would be getting a push soon and this could be that opportunity.

The United States title has somewhat been left out of the limelight, seeing Del Rio playing a more active role for the "League of Nations." While Cena returned briefly in what seemed to be an imminent rematch to be held at the coming WWE PPV, the untimely injury forced the WWE to scamper with changes.

While the match has yet to be confirmed, it would also be equally interesting if the two would also take part in the 30-man battle royal.

That is, perhaps, the most interesting part for the event, which takes place on Jan. 24, where current title-hold Roman Reigns will be facing heavy odds as he hopes to retain the belt over 29 other WWE stars.

Such came about after Reigns was able to keep the title against Sheamus at WWE Raw with WWE chairman Vince McMahon acting as special guest referee.

The same case holds true for Del Rio, though he enters that fight as an obvious favorite to retain the title unless the creative team has other things in mind.