John Cena appeared on Monday's episode of Raw and officially accepted Austin Theory's challenge for WrestleMania 39. First saying no to "the gift" Theory was offering, Cena was talked into it by the live crowd and told Theory it was perhaps the biggest mistake he'd ever made in his relatively short WWE career.

Cena showed up to open the third hour of Monday's show. He got a huge pop and was quite emotional about the love the fans were showing him. He ran to the ring and was set to talk, only to be interrupted by Theory who had his own message to deliver. Saying he had a gift for his one-time hero, Cena said no when offered the opportunity to wrestle for The United States Championship at WrestleMania 39. A stunned Theory waited for the explanation (as did the crowd) and he said, Theory wasn't ready and that nobody cared about him.

Likening himself during The Ruthless Aggression Era to what Theory is now, Cena warned the champ that pushing him toward a match was a big mistake. Theory had everything to lose because if he didn't win, it would prove he couldn't handle it. If he did, he still had the deal with the spotlight and the pressure that would come with having defeated John Cena. When Theory pushed even more, suggesting Cena was giving up and not showing hustle, loyalty, and respect for the title, the fans, or the challenge, Cena asked for the audience's help.

The WWE Universe unanimously cheered for Cena to take him on and Cena accepted. He finished with, "Remember this moment because you just made the biggest mistake of your life."

Cena is Officially On The WrestleMania Card

There were plenty of rumors Cena would be coming back to wrestle a match at this year's Showcase of the Immortals but this segment confirmed it. Even though Theory was teasing matches with other people, this was the bout everyone wanted to see and fans are going to get it. Whether Cena puts Theory over or Cena becomes the United States Champion, his being involved in this year's show ups the marquee nature of the event just that much more.

This is now two WrestleManias in a row where Theory is a huge part of a big angle. Clearly, WWE sees major potential in him. That Cena wants to work with him means the former champ does too.