During Wrestling Observer Radio, Dave Meltzer noted that there's been speculation online that perhaps Reigns would not be on the show since they have not set up an opponent for him but that is not the case and he will be there.
Meltzer stated, "He is, in fact, in the main event. I presume they’ll shoot the angle on Friday. I don’t know that as a fact, I would presume it. But he is in the main event on the WrestleMania Backlash pay-per-view."
Reigns holds the Undisputed and WWE Championship after defeating Brock Lesnar at WrestleMania in Dallas. Days later on SmackDown, Reigns and The Usos attacked Shinsuke Nakamura but there has been no hint as to who he will face at the pay-per-view.
Reigns returned to in-ring action this past week after not appearing on the recent episode of SmackDown.
As of this writing, here are the matches announced so far for WrestleMania Backlash:
Cody Rhodes vs. Seth "Freakin" Rollins
WWE Raw/SmackDown Tag Team Championship Unification Match
RK-Bro (Raw) vs. The Usos (SmackDown)
AJ Styles vs. Edge