I mean seriously, if Duke learns to hit even a minimal amount, he is a 10 year major league bench player. Yes he is raw and not ready right now, but you can't teach 80 speed. In an era where they basically made stealing 2nd base a gift, a dude like this has value if he can get into the low to mid .200s with an empty average. A soft single is basically a double in the scorebook with his speed.
Besides that, yes, you absolutely do this roster dance with a career MiLB guy you don't care about losing.