Cena and Undertaker have done battle before, but never on as grand of a stage as Wrestle Mania.
It has been considered a dream match by many for years, and now there is a realistic possibility of it coming to fruition at the upcoming installment of Wrestle Mania.
There is also a decent chance that Undertaker's appearance is merely meant to be a one-off as a way to boost ratings for the milestone episode of Smack Down.
But now would be as good of a time as any to reveal what's next for him in WWE.
Of course, Ambrose is a possibility, but that program could easily be a placeholder for Cena ahead of 'Mania.
Time is running out for WWE to capitalize on this once-in-a-lifetime matchup, and if the fantasy match does become a reality, the highly anticipated 900th episode of Smack Down Live would be the perfect place to begin planting the seeds for it at Wrestle Mania 33.
Get your first month of WWE Network for FREE: to WWE on You Tube: T Visit WWE.com: Must-See WWE videos on You Tube: https://goo.gl/Qmh Bof John Cena played to the home crowd at Wells Fargo Center on Monday night.
Meanwhile, Undertaker could be done with wrestling as soon as Wrestle Mania 33, and Cena would be a fitting final opponent for him.
16, 2009 edition of Raw, and Undertaker subsequently laid out Cena with a Tombstone piledriver.
The Phenom has faced a long list of legends over the years as well as a few fresh faces, but his career wouldn't be complete without a match against the face who runs the place at WWE's premier pay-per-view. Open gimmick was widely beloved by viewers, and his lengthy feud with Styles has been a blast as well.
Undertaker has long been an important part of the blue brand, dating back to 2002 when he became a permanent fixture on the program for well over a decade.
Currently, he is one of few remaining Superstars who has yet to sign with Smack Down or Raw, so perhaps he will finally ink a deal upon his return.