Dustin Keller was supposedly offered a multi year contract but refused to take it and chose a one year deal instead because in his estimation his free market value was hampered by his spending 2012 battling injuries, so he wanted to have a healthy productive year and recover his value. Tyson Clabo's contract being a one year deal would most likely be due to his being very old, especially for this front office which likes to keep the roster very young. I don't think he has much to prove to them. If he performs admirably they may consider re-upping him for another deal but it would most likely be yet another one year deal. Randy Starks was offered a multi year deal but he and the team could not agree on the value of it, and so the team was left no choice but to franchise him. Brent Grimes as you say has only a one year deal because it would be folly to guarantee much money over multiple years to a corner coming off an Achilles tear. The same is true of Lance Louis, who is coming off an ACL tear. The one guy that I think really was offered kind of a one year "prove it" deal strictly from a talent standpoint was Chris Clemons. They'd like to see him take the next step before they commit to him. It doesn't have anything to do with age or injuries and I don't know that it had anything to do with being unable to agree on the value of a longer term deal.
IMO, he left for one reason. StL offered him more guaranteed money. Unless someone has solid proof to the contrary, I'm going with that.
