John Cena WWE
John Cena could leave SummerSlam with no title or both the WWE World Heavyweight Championship and United States Championship. Getty

Only one match will go on last at SummerSlmam 2015, but there will essentially be two main events on the card. The Undertaker vs. Brock Lesnar will likely close out the pay-per-view, but the match between John Cena and Seth Rollins is just as big, considering both the WWE World Heavyweight Championship and United States Championship will be on the line.

With just a few weeks to go until the event at Barclays Center, it’s still not completely clear who will emerge victorious. But one of the four wrestlers stands out as the most likely to leave Brooklyn with a win.

It would be most surprising to see The Undertaker lose his first match since WrestleMania 31. The betting odds at Paddy Power list the Deadman as an odds-on favorite against Lesnar, who broke The Undertaker’s undefeated streak at WrestleMania 30. After losing to Lesnar and vowing to get his revenge, The Undertaker is bound to get his win back from the former UFC champion.

The only question might be whether The Undertaker will beat Lesnar at SummerSlam or at WrestleMania 32, where the two superstars could meet again. WWE might have other plans in mind for The Undertaker in 2016, possibly eyeing a match with Sting, which could force them to give the Phenom his win at SummerSlam. Even if WWE plans to pit The Undertaker against Lesnar at WrestleMania next year, they might want it to be the rubber match of their feud that dates back to 2014.

Lesnar would remain the most feared wrestler in WWE, despite a loss at SummerSlam. Even if he is defeated by the future Hall of Famer, he can still brag about conquering the streak, which saw The Undertaker win 21 times in a row.

The outcome for Cena vs. Rollins is much more up in the air. Both currently hold titles, and the possibility of Sheamus cashing in his Money in the Bank briefcase makes the result of the match even more difficult to predict.

There’s almost no chance Rollins will defeat Cena cleanly. It’s possible that J&J Security could return, or Rollins could be aided by some other outside interference. SummerSlam 2015 won’t see a repeat of what happened at the PPV in the last two years, as both Daniel Bryan and Lesnar defeated Cena cleanly for the company’s No.1 championship.

It’s certainly possible that Cena will defeat Rollins cleanly, just like he did on “Monday Night Raw” a few weeks ago. But it looks like Cena and Rollins might feud over the course of a few PPV’s, and a clean victory for either might not be the best way to make that happen.

There is much anticipation for both of the big matches on the card. The brawl between Lesnar and The Undertaker on “Raw” a few weeks ago has raised the level of their feud, and Cena vs. Rollins could end up being the most entertaining match on the SummerSlam card.