You can't really show any NFL Team names or logos without the proper licensing. Of course, it happens all of the time, but if the offending party (from the NFL's point of view) is making a big enough stir (or $$$) then it gets their attention.

As far as player likenesses go, that's a little bit trickier. I am guessing the NFLPA or the players themselves would have to pursue the offending party. I guess it would be best to create players that look "a lot like" someone...but need to be modified slightly to look just right.

I think Miggle has already started in the right direction...EFL teams that look very similar to NFL teams. They have even stayed away from city references with their EFL teams...but there might be some room there as well...Say you make a game cover that has black and gold "PITTSBURGH" in the end zones but no reference to the Steelers or their logo anywhere. You might be able to get away with that (although their may be some stipulations with city names and NFL uniform color combinations that I am not aware of).

My guess it that it's all pretty hairy...and it's best to either pursue the proper licensing or stay far enough away from those fuzzy areas so that you are safe.

Added comment --- just read Nat'l post...

Yeah, I think you are 100% correct with your own stuff...it's when you start to sell that it becomes an issue...