From the list of free agents above, here's my best guess which backs would be prime for CFL consideration after any cuts in July or August. Are any of these guys on a negotiation list?
These backs are for the most part still young enough to groom should they not make an NFL roster this season:
FA = Current Free Agent
Chris Jennings FA (former CFL player and with plenty of trouble off the field though)
Evan Royster FA
There are also plenty of young running backs with and without camp experience on and off this list, but these guys above for the most part at the point where if they are not playing more this coming season in the NFL, they will be likely soon out of the NFL anyway given that if they are not playing it would be far more compelling for management to replace with them with younger backs and often to pay them less.