The return of the Undertaker is nowhere near a certainty, but the possibility is being taken seriously enough that possible WrestleMania opponents are being pitched. While the planned WresteMania main event continues to be Brock Lesnar vs. Roman Reigns, Vince McMahon has expressed to his inner circle that alternatives need to be considered as Lesnar vs. Reigns would be a repeat of the main event from the WrestleMania three years prior. Of course, that match actually ended up turning into a triple threat with Seth Rollins, but nonetheless the billed match for WrestleMania 34 would be the same as WrestleMania 31, a match that the public wasn't as excited for as hoped the first time around.
Once again, the solution may be a triple threat. There have been some preliminary talks that if the Undertaker did decide to return for one more match, that WrestleMania would be headlined by Brock Lesnar vs. Roman Reigns vs. The Undertaker in a triple threat. The Undertaker would be able to attempt to avenge both of his WrestleMania defeats in the same match without having the same pressure and physical demand that comes along with a one on one match.
A lot is up in the air because with Jon Jones failing a UFC steroid test, Brock has lost his big potential UFC payday and McMahon now likes his chances a lot more in terms of being able to convince Brock to opt in to the final year of his agreement or negotiate another extension.