"Desmond is a more viable option in the OF than CarGo." 

You keep saying this as if it's some cold, hard fact, and yet it's not supported by anything I see happening on the field. Much of Cargo's defensive value in RF is from his arm, which is still good enough to deter runners from going first-to-third on a single. Anyone who's seen Desmond make a throw from the OF is going to have no such reservations, as it's often hard to tell which base he's throwing to. And while Cargo's range isn't what it used to be, I don't think his lack of stolen bases indicates he "cannot run a lick" or that he can no longer play RF. Dwight Evans, Al Kaline and Roberto Clemente won 30 Gold Gloves between them and are arguably the three best defensive RFs of all time, and none of them were base stealers. 

I highly doubt Cargo will be back next year anyway, so Bud Black's not going to face this question. But I won't be surprised if Cargo plays RF for some team at least as long as Desmond does.