In forums in general, deleting accounts is a big no no because it can also lead to unintended consequences (it might delete full threads started by a user, etc.).
So the most you should be able to ask would be for an Admin to de-activate your account. But as Roy also mentioned, SB Nation and the Forum are two separate entities, so it depends on what you're looking for.
Edit:
[dang], just noticed that this is a 7 year old bump... O.o