When Rey Mysterio finished off the first episode of SmackDown after SummerSlam with his hand raised above his head and the words “and new United States Champion!” pre-fixing his name, it turned more than a few heads across the WWE Universe simply because he wasn't supposed to be in this situation… literally.

After suffering a freak injury in his LWO vs. LWO United States Championship invitational match with his latest protege, Santos Escobar, Mysterio was fully prepared to stand in the corner of the “Emperor of Lucha Libre,” but after being attacked over and over and over again by Austin Theory over the course of the show, it became clear El Hijo del Fantasma wasn't going to be able to grapple with the US Champion, no matter how much he wanted to.

Fortunately, Mysterio went into full-on Dad mode and marched his way into the ring to give Theory a Dominik Mysterio-style spanking, an intention made all the more intriguing by Adam Pearce announcing on the spot that the WWE Hall of Famer would be taking part in the match instead of Escobar.

Was this the plan all along, with Mysterio's injury swerving the initial plans on the spot instead of intentionally giving the rub to Escobar? Or did WWE decide that it makes more sense to see another performer beat Mysterio in the future instead of Theory, maybe to give some cover to the 26-year-old from Atlanta while adding a nice, legacy-bolstering title reign to a Hall of Famer's resume? Either way, the idea of giving a 48-year-old Mysterio another title run in what may be the ninth inning of his legendary career has virtually no downside, as he's the textbook definition of a WWE transitional champion.

Rey Mysterio's United States Title run has no real downside.

So, for the sake of argument, let's say WWE would like to prove LA Knight has arrived by placing a championship belt around his waist or really define the next era of lucha libre in WWE by giving Santos Escobar his first championship reign on the main roster; how does a win over Austin Theory help with either of those opportunities?

Think about it, at this point, Theory is cold, with barely any screen time committed to his United States Championship since he was drafted onto SmackDown, and even fewer expectations of his future success as things are presently constituted. Though he didn't have a United States Championship match booked for SummerSlam, he still found a way onto the card and was unceremoniously eliminated in the Slim Jim Battle Royal as if he was a mid-card jobber instead of a legitimate champion. While giving Knight the win over Theory would have still gone over to an incredible degree, the loss would have buried the previous champion to a pretty incredible degree, as the babyface would have had to have gone over cleanly instead of with the minor asterisks that “A-Town's Finest” will likely bellyache about for the foreseeable future.

Putting Mysterio in place as a transitional champion, whether he holds the belt for a week – don't do that – a month, or even longer, would allow for the next title holder to secure the win by defeating a legitimate WWE Hall of Famer, which, depending on the performer, could have incredible implications on his future based on how WWE decides to book it. Sure, Theory could try to wrestle for the title once more, and probably will, but in case you haven't noticed, Grayson Waller has already started calling out “The Mystery” on social media and will likely double down on that take later this week when the two men share the ring, seated mind you, on The Grayson Waller Effect. Could WWE opt to give Waller a mini-detour feud with Mysterio in order to see whose rub has a strong effect on the other?

Ultimately, whether Rey Mysterio wrestles for one more year or five, the day will come in the not-too-distant future when he hangs up his boots and either passes on his mask to “Dirty Dom” or takes it with him back to San Diego for the peace of retired life. Giving him the United States Championship now when he can still go, even if it's only for a few weeks or months, will not only allow fans to enjoy the magic that is Mysterio but also set up his eventual success for an even bigger opportunity down the line that simply wasn't going to be available via a clean pinfall victory over Austin Theory.