John Cena heel turn?

Everyone has been going on about the end of the John Cena vs the Miz match, IMO there is one way to turn Cena into a heel quite easily, this is by Cena giving the Rock the FU(AA), it may turn him into a heel or it may make him a bigger face, but this could be one way to work a fued with the Rock if the Rock is "staying" in the WWE. What do you think?

Only way I can think of a heel turn would be for Cena to side with Michael Cole, similar to how WM17 ended but have Cole hand Cena a chair after The Miz has kicked out of an Attitude Adjustment and refused to tap to an STF.

Or as the Rock is scheduled for an appearance on the Raw after Wrestlemania, have a tag match with The Rock & Cena vs Miz & a partner. As Rock is looking to make a hot tag Cena drops from the apron and leaves The Rock to get a beatdown.

Or after HHH as lost to the Undertaker and has to retire, on the Raw after Wrestlemania have Cena come out and mock and humiliate HHH for his loss. This would evoke people's sympathy in HHH due to him retiring and people would turn on Cena due to these actions.