What message are u sending how to get worse. The kid is struggling with his confidence (Not effort), personally like most Yankee prospects they tend to be overhyped and not nearly as good as the hype claims they will be. the simple answer is he is a decent starter, who has a plus defensive rating by all metrics with a OPS that will probably finish somewhere in the low to mid 700's and might steal about 20 bases a year. At times he will look like he can't do anything when he can't do any right and occasionally he might have a bad day in the field because of it, although In the long run he will be plus at his position over the course of the season defensively with as I said a low to mid 700 ops with some speed.
Now Yankees fans are gonna tell you how he stinks, he doesn't he just a slightly above average ball player. He won't hurt you, but in reality volpe should be batting 8th or 9th in your order, and his defense over the long run at a important position will be fine. And the way he gets to his numbers is streaky. if you accept that, you won't be disappointed, if you expect better than you will be, point is who do you want to see in his place the other options are much worse than him on the roster right now at SS. if it was effort, I would agree with you, but it is more a lack of confidence and streakiness, and I think that is something this player will always struggle with. There are no better options, you need to trade for a 3b anyways so you can move Jazz to 2b where it is his best position. The answer is obvious though, maybe suarez will be available if the d-backs fall out of it mcmahon is starting to pick it up might also be available and he is really good defensively at the position. So in the long run in another month my guess is the yankees secure a natural 3b, and can move jazz back to 2b where he belongs in my opinion.