Perez is good in the sense that he can provide defensive value from basically any position which allows maximum roster flexibility and he occasionally has some pop off the bench. Counsell basically treats him as a de facto starter though, which is insane. BCB I think wrote something about this. The more you play Perez, the more he's exposed, so you want to limit the amount of plate appearances he gets. Edit: https://www.brewcrewball.com/2017/7/25/16021664/milwaukee-brewers-should-consider-using-hernan-perez-less-often