John Cena has been the top babyface in WWE for nearly a decade, and the idea of him turning heel has been a popular topic among wrestling fans for years. Despite calls by many for the 15-time world champion to join the dark side, Cena might never abandon his good-guy persona.

Throughout his career, Cena has joked about the possibility of a heel turn, even doing so on the edition of “Monday Night Raw,” following WrestleMania 29. In recent video that saw Cena working out with powerlifter Mark Bell, WWE’s top superstar insisted that he would never become a villain with the company.  

“Never happen,” Cena told Bell. “Not a chance. Nope.”

In past interviews, Cena has said that he doesn’t have an interest in turning heel. He did acknowledge that he could be an effective bad guy, but WWE would not want him to make a change.

“Oh, I got it in me, sure.  I do what they tell me, boss.  Never happen.”

Fans often compare Cena to Hulk Hogan, who was once the ultimate babyface and wrestling’s top star for over a decade. Two years into his run with WCW, Hogan finally turned heel, joining the NWO. The move revitalized Hogan’s career and helped WCW surpass WWE in the ratings.

Hogan recently echoed Cena’s sentiments that WWE and Vince McMahon want Cena to remain a babyface, though he personally thinks it’s time for Cena to change his character.

“I would say no,” Hogan said on Grantland’s “Cheap Heat” podcast, when asked if Cena would turn heel soon. “Vince has a better feel for that. There’s more to it than just a good guy, bad guy with Cena…it’s something that Vince knows better than anybody. For me I would say yes, but it’s apparently not time.”

Even if a heel turn for Cena could help improve WWE’s onscreen product, it might not be worth it for the company. In February, Cena granted his 400th wish with the Make-A-Wish foundation, while no celebrity has even granted 300 wishes. The 37-year-old is also, by far, WWE’s top merchandise seller. As a heel, Cena’s Make-A-Wish requests and merchandise sales could drop considerably.

“I think that's kind of the purveying attitude amongst a lot of Internet fans, but they're not thinking of the big picture of probably the amount of merchandise that Cena sells, which I think is probably 5-to-1 to the closest competitor,” Chris Jericho recently told IGN. “The people that like to chant “Cena sucks”, half of them are wearing Cena shirts. And just all the work he's done. I think he's the most requested Make-A-Wish guy ever, more than anybody else. So those are the type of things that you think about more than just having him turn heel.”

Before WWE would ever seriously consider turning Cena, they’d likely have to find his replacement as the company’s next top star, which is something they’ve been unable to do. At his peak, CM Punk was WWE’s No.2 superstar, but his overall popularity never matched Cena’s. Daniel Bryan achieved immense popularity over the past year, but his merchandise sales have never come close to Cena’s.

Roman Reigns might be the key to Cena one day turning heel. The company reportedly has hopes of him becoming the next face of WWE, and he could face Brock Lesnar at WrestleMania 31 as part of his ascension to the top of the card. However, the former Shield member has a long way to go before he proves himself worthy of being Cena’s successor.