5 title changes in WWE that must happen in 2019

#3 Rey Mysterio becomes United States Champion

Mysterio could upset the founder of Nak-America to become a Grand Slam Champion.

Rey Mysterio already has a Hall of Fame worthy career, being a former WWE, World Heavyweight, Cruiserweight, Tag Team and Intercontinental Champion.

But in 2019, the master of the 619 has the chance to finally capture the Grand Slam, if he became United States Champion.

Winning the star-spangled strap would be the cherry on the cake for Mysterio, who returned at SmackDown 1000 and has been impressive since.

In addition, having him feud with current champion Shinsuke Nakamura would make for some truly excellent viewing, as the pair's similar, but contrasting styles would certainly mesh well.

We don't know how long Mysterio will stay with the WWE now that he is back, but having him win a title would only add to the masked man's truly incredible career in the WWE.