Could it be Sam is just a lousy player?
NFL is a business like any other and if you cant do the job you get shown the door.
Its Surprising that any team drafted him because all eyes would be watching and waiting to see what you do next and ready to pounce if you show the smallest of Homophobic hints.
Slow and weak (for his position) at the combine.
When you're a 2nd/3rd stringer you need to be a good special teams player because that's how those guys are normally used. Apparently he's not.