re: When did players start wearing jerseys that stop above their navel again?

That's been going around for a few years: our DJ Swearinger did that his entire time at USC - the equipment guys would have the player's shoulder pads already inside their jerseys and on top of their lockers, ready to be put on for the game, and Swearinger would tie the bottom of his jersey up under his lower back pads, so it'd look like a belly shirt:



And then others would have their jerseys ride up whether or not they intended them to or not, like with Kelcy Quarles: