The only question is whether or not Janish has the offense to support his defense. I'm not sure about that, but I think that there's a good chance he can.
I think he needs to OPS .650 or over, and that is what he did when he had the starting job at the end of last year. I don't give much credence to his spring stats, especially since they were in hitter friendly Az, but I do think what he did as a starter last years shows that he should at least be given a chance.
At the very least, I would like to see Janish start 2 games a week, and enter most other games in the late innings for defense. As Spring~Field asks, why not give him a shot?