This is my best case scenario. I'm more concerned with immediate LB depth than CB or safety. At this time, there are only 7 linebackers on the roster:
Kelvin Sheppard - Starter in middle
Nick Barnett - Starter outside
Kirk Morrison - Starter outside
Chris White - backup outside, 6th round pick last year who had a season ending injury in week 10
Arthur Moats - backup outside, more of a rushbacker than a cover guy
Bryan Scott - backup outside, more of a safety
Scott McKillop - backup middle, ummm WHO?
Andra Davis & Reggie Torbor are both unsigned and unrestricted. Merriman is now listed as a DE.
If it's true that Keuchly can play any LB position I think he's the guy.