It would be the perfect match.
Today, the trailer for the newest and final movie in the Avengers series was released, starting the countdown to the end of the franchise. What will Marvel do with all the strands of their cinematic universe? As some of the highest grossing movies ever it seems unlikely that Disney will let these ones fall by the wayside completely, but will they'll use this as an opportunity to start fresh with some new blood. Maybe even with John Cena.
In his appearance on The Ellen Show this week, Cena addressed the frightening length of his hair, spoke some Mandarin and said, of a possible role as Cap: "if it's out there, if the Captain America people are listening and you're watching right now, I'd totally do it. I totally will, because I think I'd be a good Captain America." Referring to his hair (which he styles now that it's grown longer, making it look surprising, to say the least) he said "I've already ruined everyone's childhood, so it can't get any worse!"
Cena has already granted more wishes via the Make A Wish Foundation than anybody else (he's done more than 500) and so this one last one shouldn't be too much trouble. Please, John Cena!