Add a field to player card for "nickname"
NFL in particular seems like a place that's always been huge on nicknames. Honey Badger, Money Bsdger, Joe Cool, Johnny Footbal, Refrigerator, and on and on. Be cool to have a field where we could enter a nickname, and allow it to be added at any time, or at leaat between seasons, as a player accrues it along the way.
Be a fun little feature, no?

Oh I just thought of a cool nickname for a QB "The Surgeon".

Yeah, especially in basketball. Back in the day everybody had a nickname and we seem to be getting back to that after a decade or two of unimaginative first-initial-plus-first-syllable-of-your-last-name nicknames (D-Jax) or, even worse, the initials "nickname" (GP, AI) (which, even at that, both of those guys had the much better but criminally underused "Glove" and "Answer", respectively).