Seems like several factors just may create the perfect storm for Pena to actually get a start:
-- He's put in the grunt work of sitting on the bench for 2+ weeks with only one start (in which the Royals won and he went 2 for 4, by the way)
-- Olivo has caught 9 games in a row without a rest
-- Olivo has shown that as bad as Pena's defense may be, it can't be that much worse.