Sure, for someone like him, that is a legit worry. But that in no way negates the wisdom of DHing him when he's already proven he can't play OF. Keeping him loose between ABs is a separate issue IMO.
For all we know Eloy woulda blown out his hammy playing RF in Houston. Getting him out of the OF was always a good call. He *IS* injury prone, but as a DH he is far less likely to hurt someone else. Fewer walls to worry about running the bases too. It's not rocket science.