The life of a player on the fringe of the roster is not easy. Kerwynn Williams knows this. The running back was re-signed by the Cardinals Tuesday. He had been signed a week ago after Chris Johnson went on IR, and then when the Cardinals needed an extra tight end because Darren Fells was injured -- the Cards promoted practice squad tight end Hakeem Valles -- Williams was the one they cut, just a few hours before kickoff against the 49ers. Now that Carson Palmer is just about healthy, the Cardinals found a roster spot for Williams again, letting go of quarterback Zac Dysert.

Williams lives a tough reality. He's not a special teamer (he can return kickoffs, if needed) so he's not a guy that makes sense to be active unless you need him to run the ball. He's no longer practice-squad eligible. But he's proven many times he can run the ball, and run it well. If he had been PS-eligible, he very well would have made it over Elijhaa Penny.

But with Johnson down (at least for now; there is a chance CJ2K will return this season) Williams makes a lot of sense as an extra runner. Andre Ellington will be David Johnson's official backup, but I wouldn't be surprised if Williams finds a way to get some carries over the next few weeks.

That is, of course, assuming the Cardinals don't need to find a roster spot again.