For years, one of the big talking points in wrestling has been John Cena not turning heel, with fans begging for it to happen and believing that he would be brilliant in the role, but WWE never taking the plunge.
Of course, Cena has teased it a few times himself, but in the end, WWE decided not to turn him even though there were some massively obvious points that could have been ideal.
Nobody will know whether Cena as a heel would have worked or if it would have been a waste of time, but there were certain key moments when WWE could have tried it, and within this article, we will rank the top 10.
10 Joining The Authority
The Authority was an absolutely detested faction that managed to gain huge heel heat. Of course, John Cena was right in the middle of things, going against Triple H and the group to try and get rid of them for good.
During this time, Triple H invited Cena to join forces with the Authority and become a member of the faction. Had Cena joined forces with Triple H, he could have embraced his darker side, while WWE could have used this time to bring up another babyface talent to take down the group, which would have helped them more than it did Cena.
9 Twice In A Lifetime
The fact that John Cena and The Rock faced each other for two WrestleManias in a row was a poor decision on WWE's behalf, especially since CM Punk was clearly the person who should have been headlining the event.
However, WWE could have used this to totally change the wrestling industry by having Cena turn heel after (or during) the match, rather than have the corny and forced show of respect they ultimately went with.
Having Cena get his win back was fine, but why not have him then take out The Rock and solidify him as the top heel in the company, giving Punk a perfect major opponent to build a match against.
8 Embrace The Hate
John Cena's rivalry with Kane back in 2012 wasn't one of his finest hours, but WWE did manage to make Kane feel fresh again, with the Big Red Monster trying to pull the dark side out of the Champ.
This storyline presented an opportunity for the company to have Cena actually embrace the hate, with Kane being some form of sick and twisted mentor that could help Cena transition into a heel.
It may not have lasted forever, but it could have been a lot of fun and given fans what they wanted to see.
7 His Next Return
Even though John Cena is currently very busy away from wrestling, he has still not officially retired from professional wrestling and one more run with the company can be expected from him.
This could be a brilliant time to finally have Cena turn against the fans. Given that the WWE Universe has now changed and cheers Cena, this could be a great way for him to flip and call out the fans.
Considering Cena was seldom when he was working daily with WWE, a heel turn after finally being accepted by fans could be an interesting twist.
6 One Night Stand
This was a real turning point in John Cena's career, as this event made it incredibly obvious that fans were turning against the once-popular wrestler.
Fans had promised to riot if Cena won his One Night Stand match against Rob Van Dam, which is why WWE made the correct decision and gave RVD the win, but this could have been the perfect time to turn Cena heel.
Sure, having Cena actually win would have caused a huge scene on the night, but it would have been a major moment that could have pushed Cena as the top heel.
5 Facing The Undertaker
When John Cena called out The Undertaker for a WrestleMania match, the WWE Universe became incredibly excited about the prospect of the two legends finally doing battle on the grandest stage of them all.
Obviously, they did end up wrestling a very short match, but WWE wasted this match. With 'Taker not responding to Cena, this could have been his time to make the turn happen.
A heel John Cena facing off against a babyface Undertaker could have been unbelievable, possibly even setting the stage for the main event match.
4 Tieing Ric Flair's Record
When John Cena became a 16 time World Champion, tieing the classic record set by Ric Flair, WWE was presented with another big opportunity to turn him into a heel, using the accomplishment to depict the Champ as arrogant.
Claiming he was the greatest of all time and that nobody was ever going to compare would have been a simple way to make this championship reign memorable, especially in the lead up to WrestleMania.
Instead, WWE opted to have him drop the belt shortly after to Bray Wyatt, who went on to have an average feud with Randy Orton, while Cena ended up proposing in the middle of the ring at WrestleMania 33.
3 2005 Draft
When John Cena was drafted to Monday Night Raw in 2005, this was a major moment as he was given the chance to prove himself and be the top face of WWE's main show. Consequently, this would have been a good time to try Cena as a heel.
Cena hadn't yet become stale as a babyface; therefore, turning him at this point would have been far less risky, yet WWE opted to not take that chance.
Obviously, the company could see how much potential he had as a major babyface star in the main event scene, but having Cena become a little darker at this juncture wouldn't have been a terrible idea.
2 Joining The Nexus
The Nexus storyline was a lot of fun, although WWE didn't book it perfectly, which eventually brought their downfall. Nevertheless, their debut was great and their feud with John Cena was enjoyable.
Eventually, Wade Barrett managed to get Cena to join the group, which would have been another ideal moment for WWE to actually surprise everyone by having him fall in line with the group.
Instead, WWE opted to go for the traditional approach, with Cena taking down the group from the inside. This just felt like a huge missed opportunity to really push the group with Cena as a top heel leading them.
1 Losing To The Rock
This is the most obvious moment that WWE failed to capitalize on, with John Cena being defeated by the Rock in arguably the biggest match of his career.
Cena and Rock had built this storyline for an entire year, with the People's Champion winning in a result that should have changed Cena forever, presenting the perfect event to turn him heel.
Having this loss change Cena totally would have made their second match the year after far more interesting; instead, WWE opted to bring Brock Lesnar back and have him attack Cena, keeping him as exactly the same character as before.