Steve Keim said the one-year contract under which running back Chris Johnson is now playing is “something we will look at” in terms of a potential extension. That sounds about right — as good as Johnson has been, Keim and the Cardinals are very careful with older veterans who they have signed to one-year deals, and regardless of how well they play, the Cards will be smart with further contract offers (see Dansby, Karlos and Cromartie, Antonio.) They will have a number they are comfortable with, and if it isn’t good enough for Johnson, the Cardinals will be ready to move on. That’s the model.
http://blog.azcardinals.com/2015/10/12/keim-cj-just-hitting-his-stride/