31% k rate in AAA isn't great...
FWIW, Duran is starting to catch up to him OPS wise. Duran is at 1.015 with Cordero cooling down to 1.111.
What I would do is call up Cordero and give him 2 weeks to see if he can rebound at all. If he can't, just DFA him off the 40 man roster. At that point, I'd call up Duran.