Just thought I'd provide this link to a MMORPG Football game. It's pretty cool and it helps take the edge off your "Football Jones" until the NFL season begins.
You can create a player and build him through skill points and XP points. There is no cost unless you want to buy more skill points. But there is no obligation to do so whatsoever. And I haven't been spammed by anything either. I've got three players playing on three different teams. A HB, A ROLB and a TE.
If you like to manage a player and see how he develops, this is a fun way to do it. A few guys at my work are in this as well.
Here's the link to Goal Line Blitz.