For the sake of argument, let's say it Roosevelt you keep instead of Smith since that would be a popular choice. What do you lose?
Wildcat - Cannot a mobile Qb that can throw better than Smith like T-Jax minimize the loss here, if not completely negate it?
WR - Smith is a way below average WR, and looks stiff out there... Naaman all the way here
Returns - We have plenty of KR guys already, they generally don't have long shelf-lives, many kicks aren't even returned anymore and Smith hasn't looked good doing that for us yet. Punt returns are both more valuable and difficult and Roosevelt has looked good doing it. Edge Roosevelt.
Coverage - Okay, B.Smith is good at covering kicks, but do we need a 4 million dollar coverage guy? And if they keep Potter, almost no need anyway.
So sure, he can do 4 things, but none of them better than people we'd have on the roster.... You would, without question, lose someone better at something he does, by keeping him. And now with a groin pull, probably would not even play for a while!!!