WWE Superstar John Cena will retire next month, with his final match set for the upcoming edition of Saturday Night's Main Event. He recently announced a major 16-man tournament to determine his last opponent. Fans have been eagerly anticipating who will be the legend's last opponent.During the announcement, The Cenation Leader made an intriguing statement, where he mentioned that stars who don't work in the Stamford-based company will also participate in the tournament. Many fans believe this may be a tease for the return of Adam Copeland or Chris Jericho. Fans have constantly been talking about these two stars returning and facing The Greatest of All Time one last time.According to Wrestling Observer Radio's journalist Dave Meltzer, WWE is deliberately teasing Adam Copeland or Chris Jericho's return. However, the two will not be a part of the tournament."They want to get people to tease the idea that it’ll be Adam Copeland, which it will not be. [Or Jericho] Which it will not be there either, because his contract’s not due then. So, I mean, it’s going to end up being, you know, Matt Cardona or somebody like that," he said. [H/T - Ringside News]John Cena discusses his in-ring abilitiesThe Cenation Leader has given the pro wrestling world some incredible performances throughout his retirement tour. However, he might not be able to keep up the same energy in the future.While speaking with Tom Rinaldi, John Cena said that he wouldn't wrestle again after promising he would step down once he couldn't keep up with the product."I made a promise to WWE that I would not stick around when my skills can't match the product, and they can't, and that's ok, because what I do isn't who I am. The realization of that has helped me be like, 'let these guys have it now.' Physical activity, 100%. I very rarely speak in absolutes because you never know. I do know in this case. Never again, because I don't want to let the people I made a promise to down," he said.It will be interesting to see who John Cena's final opponent is.