Heart and soul or not, in a vacuum it's hard to justify Naylor and his 60 wRC+ vs lefties (53 this year) starting games against tough lefties. Thing is though, nobody has really established themselves as a great alternative. Owen Miller with a solid 72 this year... Putting a kid with little experience there (Arias) isn't exactly the solution either, and he has bad splits as well (32% K vs lefties).
It would honestly be awesome if Amed could play 1B, then just stick Arias at SS, problem solved. But he can't either.
Hopefully something that is solved in the offseason.
Meanwhile, Will Brennan has some pretty severe splits vs lefties this year (.254/.313/.339) vs (.333/.389/.518) vs righties. He will probably be the casualty while Naylor and Miller play. Just my guess. I could live with it.