John Cena turned 37 years old on April 23rd. He's closer to the end of his career than he is to the beginning. It's weird to think of that way, but that's just the reality of the wrestling business. While Cena is still in incredible shape and has shown no signs of slowing down, he has to start thinking about his future. That doesn't mean he's a guy that is going to retire within the next two years. If it was an athlete in football, basketball, soccer, baseball or something like that then he'd be at the age where retirement is something to consider. However, in pro wrestling we've often seen guys wrestle well into their 40s. The Undertaker is 49 years old and he has obviously slowed down significantly, but he's still competing. Shawn Michaels retired at 45 wrestled Ric Flair is an exception that wrestled into his 60s. Even Vince McMahon was having matches in his 60s. Then there are guys like Steve Austin that retired at 39 and Edge was 37 when he was forced to stop. Nobody can last forever There's no telling how long Cena can go, but we know that he's always going to be in tremendous shape because that's the kind of guy he is. As we think about his future, several questions come to mind. How many more WrestleMania main events? Will he win the WWE Title again? How about a heel turn? Here's a look at what's in the wrestling future of the great John Cena.