If anything, this weekend showed the extreme lack of speed off the bench for this team, at least two times a PR could have been used to help this offense late in a close game.
I think with Rocco's current player usage there is absolutely a spot on this team for Kiersey, just not with a bat in his hands. Castro or Lee can play 3B with the other at 2B, and the team also has Clemens and Bride. Kiersey can PR and/or sub late for defense.
Not an ideal situation having a guy for PR or defense only (other teams have done it, successfully) , but Lewis is lost and not hitting and Rocco is basically running the same guys out there every day.