SummerSlam cheat sheet: SmackDown Live stars have much to prove

SummerSlam week has finally arrived, with the WWE set to take over Brooklyn's Barclays Center for four days of festivities.

The supershow card, featuring stars from both Raw and SmackDown, features the culmination of several key rivalries and, in all likelihood, will plant the seeds for several storylines that won't play out entirely until next year's WrestleMania.

With that in mind, we're breaking down every match on the SummerSlam card, with a particular focus on the two major titles for each show -- the Universal championship, Raw women's championship, WWE championship and SmackDown women's championship.

The rest of the card is equally stacked. Take a look below and see what the superstars of SmackDown Live have in store for Sunday.

For everything else you need to know about SummerSlam, click here.

United States championship: AJ Styles vs. Kevin Owens

There are two obvious questions here: First, is Styles going to retain the title he has taken from Owens twice since the beginning of July? And second, how will special guest referee Shane McMahon factor into the result?

We'll start with the second question first. Clearly there's been a good amount of build and not-so-subtle hints that McMahon, the SmackDown Commissioner by day, is willing to, uh, overstep his referee responsibilities and engage in any pugilistic activities with whoever might lay a hand on him, whether it's Owens or Styles.

Also, McMahon doesn't exactly have a history of being an impartial ref. Look no further than his antics when he refused to give Stone Cold Steve Austin the three count against Mankind at Survivor Series. Granted, that was 19 years ago, but we were starkly reminded of that by KO at SmackDown a couple of weeks ago.

So, Shane, are you going to call this one down the middle? Probably not.

Owens and Styles have been intertwined in various storylines since the Superstar shakeup in April. But the real heat began at Battleground, when Owens pinned Styles for the title, only to lose it two days later. Conventional thinking suggests Styles will come out on top, with McMahon possibly playing a role in the outcome, thus setting up a feud with Owens. But as we've seen in this rivalry, nothing seems to go as planned, especially when you have titles between the two changing at house shows.

John Cena vs. Baron Corbin

Not a single person will enter SummerSlam with more regret than Corbin, not after he failed to cash in his briefcase Tuesday and walk away with gold.

A devious plan to leverage his free shot for the title backfired when Corbin went to pin a seemingly down-and-out Jinder Mahal, only for the champ to collect himself and roll up Corbin for the win. Corbin was beyond angry, and the question now is whether he can maximize that anger and take it out on Cena.

As with WrestleMania, Cena will not be the star attraction at SummerSlam. Not even close. But his presence alone makes this match against Corbin that much more appealing. It's hard to imagine Cena, despite the fact that he has lost his past six SummerSlam matches, would let Corbin get over on him, especially considering that the 16-time champ just went down cleanly to Shinsuke Nakamura in a No. 1 contenders match. There's only so much beating a legend can take, right?

For Corbin, it's hard to imagine him being thrust into the championship spotlight anytime soon if he were to not only fall to Cena, but do so without a briefcase to fall back on.

SmackDown tag team championship: The New Day vs. The Usos

These two teams have had tremendous chemistry lately, starting at Battleground, where The New Day won their first SmackDown tag-team titles. Even a seemingly filler match Tuesday on SmackDown was entertaining. But after their 124-day reign as champs, it seems doubtful The Usos would reclaim the titles. More bad news for Jey and Jimmy Uso: They have fallen in each of their previous three pay-per-view matches against The New Day. The only potential swerve here is if Kofi Kingston were to be a factor. On Tuesday, Daniel Bryan made it clear that Kingston would be the odd man out at SummerSlam. Hmmm.

Randy Orton vs. Rusev

There's not a ton of history between Orton and Rusev, but the build between the two has been intriguing. Two weeks ago, Rusev attacked Orton as SmackDown came to a close, and just the other day, Orton landed a perfectly timed RKO on his Bulgarian opponent, and yes, it was out of nowhere.

Given an injury and long layoff after the brand shakeup, Rusev has not had a lot of TV exposure in recent months, and the one high-profile event he was in at Battleground was an underwhelming loss against John Cena.

As for Orton, he hopes he can make up for a confounding loss a year ago at SummerSlam, when Brock Lesnar busted The Viper's head open, a wound that caused the match to end prematurely. Orton hasn't won a SummerSlam match since 2013, when he cashed in his Money in the Bank briefcase to take the title from Daniel Bryan.

Despite Orton's dubious numbers and Rusev's lackluster existence lately, this match is as tough to call as any on the SummerSlam card.