My son had the yips like this once, we had him put the ball cap in his mouth and bite the bill of the cap. Make sure the cap is upside down and with the logo facing your chin. It forces you to watch ball into the glove and if your hands are out front...you should be okay. If you do it right, you will have to face down as the ball is in the glove and it is really difficult to lift the head up and see the ball during that process unless you focus.
He could make "jeter-esque" plays that no one else could make but those 8 hoppers ate him up for a while. No he attacks every ball and if they are hoppers, he makes a quick decision to attack on a certain hop.
Best of luck to you.