I guess Vogey couldn't hit in the second half because of this

[Moe Gibbs]

Hitting against [and failing against] Left handed pitching could have helped to erode his overall confidence and ability to get 8 hours of uninterrupted sleep as well.
He is pretty close to being a valuable player..if only he would commit himself to getting into better shape and if his management is capable of taking him to the next level with "cutting edge" coaching.
His defensive skills at first base were not awful, just limited by the amount of dead fucking main artery clogging weight that he has chosen to carry around 24/7/365

[D-train]

I would say it had more to do with the fact that early in the year he was platooning and pretty much only hit against right handed pitching. As soon as they made him an every day player his numbers nose dived. For the year he had a 124 OPS+ against right handers, 59 OPS + against lefties.

I think his numbers vs. Righties fell like a rock as well. Or did you mean that he couldn't handle playing every day.