I bet Faulk stays because they don't believe they have a viable bach-up to run their system. Canidate has really dissapointed them since he was drafted, sure he showed he has a bit of big play potential, but as an inside the tackles runner, he gives you VERY little.
Rookie Lamar Gordon has potential, but nobody thinks he will ever make an impact like Faulk.
I bet he signs a big long term deal with the Rams that has some out clauses after 3 or 4 years.